ENGINE PERFORMANCE – GMC Cab & Chassis C2500 1994 – SYSTEM WIRING DIAGRAMS

ENGINE PERFORMANCE

4.3L

4.3L (VIN Z), Engine Performance Wiring Diagrams, A/T (1 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 4.3L (VIN Z), Engine Performance Wiring Diagrams, A/T (1 of 3) for GMC Cab & Chassis C2500 1994:

• (4l60e)
• (4l80e)
• (left top front
• 12v battery
• 12v ignition
• 5v return a
• 5v return b
• 5v sensor ref
• A/c on signal in
• A10
• A11
• A12
• A13
• A14
• A15
• A16
• Air condition- ing system
• B10
• B11
• B12
• B13
• B14
• B15
• B16
• Brake sw to pcm
• C215
• C218
• Coolant temp sensor
• Cruise control system
• Cruise ind reg grd
• Distributor ref hi
• Distributor ref lo
• Dlc
• Dlc serial data
• E10
• E11
• E12
• E13
• E14
• E15
• E16
• Ecm-ign fuse 10a
• Egr electronic vacuum regulator solenoid valve (4.3l w/nrq & a/t or 5.7l w/ 4l80e only) (right top of engine)
• Egr valve solenoid
• Egr valve solenoid (4l60e only) (left rear top of engine)
• Elec fuel pump in
• Engine control module (under right side of i/p)
• Evap canister purge ctrl
• Evaporative canister purge solenoid (nb2, nrq & w/ 4l60e only) (on engine)
• F10
• F11
• F12
• F13
• F14
• F15
• F16
• Fuel pump relay ctrl
• Fuse block
• G110
• G110 (left top front of engine)
• Hot in run
• Hot in run, bulb
• Idle air control unit (right rear of tbi unit)
• Ignition bypass
• Ignition control (ic)
• Inj fuse 10a
• Knock sensor in
• Lo side inj a
• Lo side inj b
• Map sensor in
• Mil indicator ctrl
• Of engine)
• Only
• Or start
• Oxygen sensor hi
• Oxygen sensor lo
• Pcm to trans temp sensor
• Pcm trans force mtr hi
• Pcm trans force mtr lo
• Pcm trans range a
• Pcm trans range b
• Pcm trans range c
• Pcm trans shift sol a
• Pcm trans shift sol b
• Pnk
• Red
• Stepper coil a hi
• Stepper coil a lo
• Stepper coil b hi
• Stepper coil b lo
• System ground
• Tan
• Tcc clutch ctrl
• Test, or start
• Throttle body fuel injector #1 (top of throttle body unit)
• Throttle body fuel injector #2 (top of throttle body unit)
• Throttle position sensor in
• Trans input speed in hi
• Trans input speed in lo
• Trans shift 3/2 solenoid (4l60e only)
• Transmission input shaft speed sensor (4l80e only) (left side of trans- mission)
• Vss buffer signal
• Yukon & suburban

4.3L (VIN Z), Engine Performance Wiring Diagrams, A/T (2 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 4.3L (VIN Z), Engine Performance Wiring Diagrams, A/T (2 of 3) for GMC Cab & Chassis C2500 1994:

• (4.3l only)
• (center rear
• Accy
• Bulb test
• Distributor
• Engine coolant temperature sensor (right top front of engine)
• Fuse block
• Gauges fuse 20a
• Hot at all times
• Hot in run, bulb test, or start
• Ignition coil (center rear of engine)
• Ignition switch
• Instrument cluster
• Knock sensor (4.3l only) (rear of engine)
• Knock sensor (right side of engine, below exhaust manifold)
• Lock
• Manifold absolute pressure sensor (right rear top of engine)
• Nca
• Of engine)
• Off
• Pnk
• Red
• Run
• Service engine soon indicator
• Start
• Tachometer test lead
• Tcc/brake switch (top of brake pedal bracket)
• Throttle position sensor (right side of throttle body)

4.3L (VIN Z), Engine Performance Wiring Diagrams, A/T (3 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 4.3L (VIN Z), Engine Performance Wiring Diagrams, A/T (3 of 3) for GMC Cab & Chassis C2500 1994:

• (4l60e
• (4l60e) t
• (4l80e) s
• 3-2 shift solenoid (4l60e only)
• 4.3l all or w/ nrq
• 4wd fuse 25a
• All
• C12
• C13
• C14
• C15
• Cluster
• Data link connector (under left side of i/p)
• Electronic 4-speed automatic overdrive transmission
• Fuel pump and sender
• Fuel pump in-line fuse 20a
• Fuel pump oil pressure switch (left rear of engine, near exhaust manifold)
• Fuel pump relay (right rear of engine compartment, near battery junction block)
• Fuse block
• G110 (left top front of engine)
• G117 (rear of right cylinder head)
• Heated oxygen sensor (in exhaust y-pipe)
• Hot at all times
• Hot in run
• Hot in run or start
• Instrument
• Oil press in
• Only)
• Other
• Pnk
• Pressure control solenoid
• Range mode selector
• Red
• Shift sole- noid 1-2
• Shift solenoid 2-3
• Tach in
• Tan
• Torque converter clutch solenoid
• Trans fuse 10a
• Trans- mission temp sensor
• Vehicle speed sensor (left rear side of transmission)
• Vehicle speed sensor buffer (under right end of i/p)
• Vss in
• W/ 4l60e
• W/ 4l80e

4.3L (VIN Z), Engine Performance Wiring Diagrams, M/T (1 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 4.3L (VIN Z), Engine Performance Wiring Diagrams, M/T (1 of 3) for GMC Cab & Chassis C2500 1994:

• (4.3l only)
• (7.4l only)
• (left top front
• 12v battery
• 12v ignition
• 5v return a
• 5v return b
• 5v sensor ref
• A/c on signal in
• A10
• A11
• A12
• A13
• A14
• A15
• A16
• Air conditioning system
• B10
• B11
• B12
• B13
• B14
• B15
• B16
• Brake sw to pcm
• C215
• C218
• Coolant temp sensor
• Cruise control system
• Cruise ind reg grd
• Distributor ref hi
• Distributor ref lo
• Dlc
• Dlc serial data
• E10
• E11
• E12
• E13
• E14
• E15
• E16
• Ecm-ign fuse 10a
• Egr valve solenoid
• Egr valve solenoid (4.3l only) (left rear top of engine)
• Elec fuel pump in
• Engine control module (under right side of i/p)
• Evap canister purge ctrl
• Evaporative canister purge solenoid (on engine)
• F10
• F11
• F12
• F13
• F14
• F15
• F16
• Fuel pump relay ctrl
• Fuse block
• G110
• Hot in run
• Hot in run, bulb
• Idle air control unit (right rear of tbi unit)
• Ignition bypass
• Ignition control (ic)
• Inj fuse 10a
• Knock sensor in
• Linear egr position in
• Lo side inj a
• Lo side inj b
• Map sensor in
• Mil indicator ctrl
• Of engine)
• Or start
• Oxygen sensor hi
• Oxygen sensor lo
• Red
• Stepper coil a hi
• Stepper coil a lo
• Stepper coil b hi
• Stepper coil b lo
• System ground
• Tan
• Test, or start
• Throttle actuator ctrl
• Throttle body fuel injector #1 (top of throttle body unit)
• Throttle body fuel injector #2 (top of throttle body unit)
• Throttle position sensor in
• Upshift ind ctrl
• Vss buffer signal

4.3L (VIN Z), Engine Performance Wiring Diagrams, M/T (2 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 4.3L (VIN Z), Engine Performance Wiring Diagrams, M/T (2 of 3) for GMC Cab & Chassis C2500 1994:

• (4.3l only)
• (center rear
• Accy
• Bulb test
• Distributor
• Engine coolant temperature sensor (right top front of engine)
• Fuse block
• Gauges fuse 20a
• Hot at all times
• Hot in run, bulb test, or start
• Ignition coil (center rear of engine)
• Ignition switch
• Instrument cluster
• Knock sensor (4.3l only) (rear of engine)
• Knock sensor (right side of engine, below exhaust manifold)
• Linear egr regulator solenoid valve (7.4l only) (right top of engine)
• Lock
• Manifold absolute pressure sensor (right rear top of engine)
• Nca
• Of engine)
• Off
• Pnk
• Run
• Service engine soon indicator
• Start
• Tachometer test lead
• Tcc/brake switch (top of brake pedal bracket)
• Throttle position sensor (right side of throttle body)
• Up- shift indic- ator

4.3L (VIN Z), Engine Performance Wiring Diagrams, M/T (3 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 4.3L (VIN Z), Engine Performance Wiring Diagrams, M/T (3 of 3) for GMC Cab & Chassis C2500 1994:

• (4.3l only)
• (4.3l)
• (7.4l)
• 4wd fuse 25a
• C12
• C13
• C14
• C15
• Cluster
• Data link connector (under left side of i/p)
• Fuel pump and sender
• Fuel pump in-line fuse 20a
• Fuel pump oil pressure switch (left rear of engine, near exhaust manifold)
• Fuel pump relay (right rear of engine compartment, near battery junction block)
• Fuse block
• G110 (left top front of engine)
• G117 (rear of right cylinder head)
• Heated oxygen sensor (4.3l) (in exhaust y-pipe)
• Hot at all times
• Hot in run
• Instrument
• Oil press in
• Oxygen sensor (7.4l) (left exhaust manifold)
• Red
• Tach in
• Tan
• Throttle actuator solenoid (7.4l only) (on throttle body unit)
• Vehicle speed sensor (left rear side of transmission)
• Vehicle speed sensor buffer (under right end of i/p)
• Vss in

5.0L

5.0L (VIN H), Engine Performance Wiring Diagrams, A/T (1 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 5.0L (VIN H), Engine Performance Wiring Diagrams, A/T (1 of 3) for GMC Cab & Chassis C2500 1994:

• (4l60e)
• (4l80e)
• (left top front
• 12v battery
• 12v ignition
• 5v return a
• 5v return b
• 5v sensor ref
• A/c on signal in
• A10
• A11
• A12
• A13
• A14
• A15
• A16
• Air condition- ing system
• B10
• B11
• B12
• B13
• B14
• B15
• B16
• Brake sw to pcm
• C215
• C218
• Coolant temp sensor
• Cruise control system
• Cruise ind reg grd
• Distributor ref hi
• Distributor ref lo
• Dlc
• Dlc serial data
• E10
• E11
• E12
• E13
• E14
• E15
• E16
• Ecm-ign fuse 10a
• Egr electronic vacuum regulator solenoid valve (4.3l w/nrq & a/t or 5.7l w/ 4l80e only) (right top of engine)
• Egr valve solenoid
• Egr valve solenoid (4l60e only) (left rear top of engine)
• Elec fuel pump in
• Engine control module (under right side of i/p)
• Evap canister purge ctrl
• Evaporative canister purge solenoid (nb2, nrq & w/ 4l60e only) (on engine)
• F10
• F11
• F12
• F13
• F14
• F15
• F16
• Fuel pump relay ctrl
• Fuse block
• G110
• G110 (left top front of engine)
• Hot in run
• Hot in run, bulb
• Idle air control unit (right rear of tbi unit)
• Ignition bypass
• Ignition control (ic)
• Inj fuse 10a
• Knock sensor in
• Lo side inj a
• Lo side inj b
• Map sensor in
• Mil indicator ctrl
• Of engine)
• Only
• Or start
• Oxygen sensor hi
• Oxygen sensor lo
• Pcm to trans temp sensor
• Pcm trans force mtr hi
• Pcm trans force mtr lo
• Pcm trans range a
• Pcm trans range b
• Pcm trans range c
• Pcm trans shift sol a
• Pcm trans shift sol b
• Pnk
• Red
• Stepper coil a hi
• Stepper coil a lo
• Stepper coil b hi
• Stepper coil b lo
• System ground
• Tan
• Tcc clutch ctrl
• Test, or start
• Throttle body fuel injector #1 (top of throttle body unit)
• Throttle body fuel injector #2 (top of throttle body unit)
• Throttle position sensor in
• Trans input speed in hi
• Trans input speed in lo
• Trans shift 3/2 solenoid (4l60e only)
• Transmission input shaft speed sensor (4l80e only) (left side of trans- mission)
• Vss buffer signal
• Yukon & suburban

5.0L (VIN H), Engine Performance Wiring Diagrams, A/T (2 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 5.0L (VIN H), Engine Performance Wiring Diagrams, A/T (2 of 3) for GMC Cab & Chassis C2500 1994:

• (4.3l only)
• (center rear
• Accy
• Bulb test
• Distributor
• Engine coolant temperature sensor (right top front of engine)
• Fuse block
• Gauges fuse 20a
• Hot at all times
• Hot in run, bulb test, or start
• Ignition coil (center rear of engine)
• Ignition switch
• Instrument cluster
• Knock sensor (4.3l only) (rear of engine)
• Knock sensor (right side of engine, below exhaust manifold)
• Lock
• Manifold absolute pressure sensor (right rear top of engine)
• Nca
• Of engine)
• Off
• Pnk
• Red
• Run
• Service engine soon indicator
• Start
• Tachometer test lead
• Tcc/brake switch (top of brake pedal bracket)
• Throttle position sensor (right side of throttle body)

5.0L (VIN H), Engine Performance Wiring Diagrams, A/T (3 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 5.0L (VIN H), Engine Performance Wiring Diagrams, A/T (3 of 3) for GMC Cab & Chassis C2500 1994:

• (4l60e
• (4l60e) t
• (4l80e) s
• 3-2 shift solenoid (4l60e only)
• 4.3l all or w/ nrq
• 4wd fuse 25a
• All
• C12
• C13
• C14
• C15
• Cluster
• Data link connector (under left side of i/p)
• Electronic 4-speed automatic overdrive transmission
• Fuel pump and sender
• Fuel pump in-line fuse 20a
• Fuel pump oil pressure switch (left rear of engine, near exhaust manifold)
• Fuel pump relay (right rear of engine compartment, near battery junction block)
• Fuse block
• G110 (left top front of engine)
• G117 (rear of right cylinder head)
• Heated oxygen sensor (in exhaust y-pipe)
• Hot at all times
• Hot in run
• Hot in run or start
• Instrument
• Oil press in
• Only)
• Other
• Pnk
• Pressure control solenoid
• Range mode selector
• Red
• Shift sole- noid 1-2
• Shift solenoid 2-3
• Tach in
• Tan
• Torque converter clutch solenoid
• Trans fuse 10a
• Trans- mission temp sensor
• Vehicle speed sensor (left rear side of transmission)
• Vehicle speed sensor buffer (under right end of i/p)
• Vss in
• W/ 4l60e
• W/ 4l80e

5.0L (VIN H), Engine Performance Wiring Diagrams, M/T (1 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 5.0L (VIN H), Engine Performance Wiring Diagrams, M/T (1 of 2) for GMC Cab & Chassis C2500 1994:

• (5.7l hd only)
• (a/c compressor clutch)
• 12v battery
• 12v ignition
• 5v sensor ref
• A/c on signal in
• A10
• A11
• A12
• Air conditioning system
• Air switch solenoid
• Air switch solenoid (5.0l & 5.7l- pickup only) (right front of engine)
• Anti-lock brake system
• B10
• B11
• B12
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• C216
• Coolant temp sens sig
• Crank fuse 5a
• Crank signal
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Data link connector (under left side of i/p)
• Distributor ref hi
• Distributor ref lo
• Dlc diagnostic test
• Dlc serial data
• Ecm-ign fuse 10a
• Egr solenoid
• Engine control module (under right side of i/p)
• Exhaust gas recirculation solenoid (5.0l & 5.7l ld only) (left rear top of engine)
• Fuel pump relay ctrl
• Fuel pump signal input
• Fuse block
• Gauges fuse 20a
• Hot at all times
• Hot in run, bulb test, or start
• Hot in start
• Iac coil a hi
• Iac coil a lo
• Iac coil b hi
• Iac coil b lo
• Ic bypass
• Idle air control unit (right rear of tbi unit)
• Ignition control (ic)
• Inj fuse 10a
• Injector 1 driver
• Injector 2 driver
• Instrument cluster
• Map 5v sensor ground
• Map sensor signal
• Mil indicator ctrl
• Oxygen sensor (left side exhaust manifold)
• Oxygen sensor ground
• Oxygen sensor signal
• Red
• Sensor return ground
• Service engine soon indicator
• Spark retard signal
• System ground
• Tan
• Throttle body fuel injector #1 (top of throttle body unit)
• Throttle body fuel injector #2 (top of throttle body unit)
• Tp sensor signal
• Up- shift lamp
• Upshift lamp ctrl
• Vss buffer signal

5.0L (VIN H), Engine Performance Wiring Diagrams, M/T (2 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 5.0L (VIN H), Engine Performance Wiring Diagrams, M/T (2 of 2) for GMC Cab & Chassis C2500 1994:

• (center rear
• Accy
• Bulb test
• C12
• C14
• C15
• Distributor
• Egr elec- tronic vacuum regulator solenoid (5.7l hd only) (right top of engine)
• Engine coolant temperature sensor (right top front of engine)
• Fuel pump and sender
• Fuel pump in-line fuse 20a
• Fuel pump oil pressure switch (left rear of engine, near exhaust manifold)
• Fuel pump relay (right rear of engine compartment, near battery junction block)
• G110 (left top front of engine)
• G125 (top front center of engine)
• Hot at all times
• Ignition coil (center rear of engine)
• Ignition switch
• Instrument cluster
• Knock sensor (right side of engine, below exhaust manifold)
• Knock sensor module (above right side rocker cover)
• Lock
• Manifold absolute pressure sensor (right rear top of engine)
• Nca
• Of engine)
• Off
• Oil press in
• Pnk
• Red
• Run
• Start
• Tach in
• Tachometer test lead
• Tan
• Throttle position sensor (right side of throttle body)
• Vehicle speed sensor (left rear side of transmission)
• Vehicle speed sensor buffer (under right side end of i/p)
• Vss in

5.7L

5.7L (VIN K), Engine Performance Wiring Diagrams, A/T (1 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 5.7L (VIN K), Engine Performance Wiring Diagrams, A/T (1 of 3) for GMC Cab & Chassis C2500 1994:

• (4l60e)
• (4l80e)
• (left top front
• 12v battery
• 12v ignition
• 5v return a
• 5v return b
• 5v sensor ref
• A/c on signal in
• A10
• A11
• A12
• A13
• A14
• A15
• A16
• Air condition- ing system
• B10
• B11
• B12
• B13
• B14
• B15
• B16
• Brake sw to pcm
• C215
• C218
• Coolant temp sensor
• Cruise control system
• Cruise ind reg grd
• Distributor ref hi
• Distributor ref lo
• Dlc
• Dlc serial data
• E10
• E11
• E12
• E13
• E14
• E15
• E16
• Ecm-ign fuse 10a
• Egr electronic vacuum regulator solenoid valve (4.3l w/nrq & a/t or 5.7l w/ 4l80e only) (right top of engine)
• Egr valve solenoid
• Egr valve solenoid (4l60e only) (left rear top of engine)
• Elec fuel pump in
• Engine control module (under right side of i/p)
• Evap canister purge ctrl
• Evaporative canister purge solenoid (nb2, nrq & w/ 4l60e only) (on engine)
• F10
• F11
• F12
• F13
• F14
• F15
• F16
• Fuel pump relay ctrl
• Fuse block
• G110
• G110 (left top front of engine)
• Hot in run
• Hot in run, bulb
• Idle air control unit (right rear of tbi unit)
• Ignition bypass
• Ignition control (ic)
• Inj fuse 10a
• Knock sensor in
• Lo side inj a
• Lo side inj b
• Map sensor in
• Mil indicator ctrl
• Of engine)
• Only
• Or start
• Oxygen sensor hi
• Oxygen sensor lo
• Pcm to trans temp sensor
• Pcm trans force mtr hi
• Pcm trans force mtr lo
• Pcm trans range a
• Pcm trans range b
• Pcm trans range c
• Pcm trans shift sol a
• Pcm trans shift sol b
• Pnk
• Red
• Stepper coil a hi
• Stepper coil a lo
• Stepper coil b hi
• Stepper coil b lo
• System ground
• Tan
• Tcc clutch ctrl
• Test, or start
• Throttle body fuel injector #1 (top of throttle body unit)
• Throttle body fuel injector #2 (top of throttle body unit)
• Throttle position sensor in
• Trans input speed in hi
• Trans input speed in lo
• Trans shift 3/2 solenoid (4l60e only)
• Transmission input shaft speed sensor (4l80e only) (left side of trans- mission)
• Vss buffer signal
• Yukon & suburban

5.7L (VIN K), Engine Performance Wiring Diagrams, A/T (2 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 5.7L (VIN K), Engine Performance Wiring Diagrams, A/T (2 of 3) for GMC Cab & Chassis C2500 1994:

• (4.3l only)
• (center rear
• Accy
• Bulb test
• Distributor
• Engine coolant temperature sensor (right top front of engine)
• Fuse block
• Gauges fuse 20a
• Hot at all times
• Hot in run, bulb test, or start
• Ignition coil (center rear of engine)
• Ignition switch
• Instrument cluster
• Knock sensor (4.3l only) (rear of engine)
• Knock sensor (right side of engine, below exhaust manifold)
• Lock
• Manifold absolute pressure sensor (right rear top of engine)
• Nca
• Of engine)
• Off
• Pnk
• Red
• Run
• Service engine soon indicator
• Start
• Tachometer test lead
• Tcc/brake switch (top of brake pedal bracket)
• Throttle position sensor (right side of throttle body)

5.7L (VIN K), Engine Performance Wiring Diagrams, A/T (3 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 5.7L (VIN K), Engine Performance Wiring Diagrams, A/T (3 of 3) for GMC Cab & Chassis C2500 1994:

• (4l60e
• (4l60e) t
• (4l80e) s
• 3-2 shift solenoid (4l60e only)
• 4.3l all or w/ nrq
• 4wd fuse 25a
• All
• C12
• C13
• C14
• C15
• Cluster
• Data link connector (under left side of i/p)
• Electronic 4-speed automatic overdrive transmission
• Fuel pump and sender
• Fuel pump in-line fuse 20a
• Fuel pump oil pressure switch (left rear of engine, near exhaust manifold)
• Fuel pump relay (right rear of engine compartment, near battery junction block)
• Fuse block
• G110 (left top front of engine)
• G117 (rear of right cylinder head)
• Heated oxygen sensor (in exhaust y-pipe)
• Hot at all times
• Hot in run
• Hot in run or start
• Instrument
• Oil press in
• Only)
• Other
• Pnk
• Pressure control solenoid
• Range mode selector
• Red
• Shift sole- noid 1-2
• Shift solenoid 2-3
• Tach in
• Tan
• Torque converter clutch solenoid
• Trans fuse 10a
• Trans- mission temp sensor
• Vehicle speed sensor (left rear side of transmission)
• Vehicle speed sensor buffer (under right end of i/p)
• Vss in
• W/ 4l60e
• W/ 4l80e

5.7L (VIN K), Engine Performance Wiring Diagrams, M/T (1 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 5.7L (VIN K), Engine Performance Wiring Diagrams, M/T (1 of 2) for GMC Cab & Chassis C2500 1994:

• (5.7l hd only)
• (a/c compressor clutch)
• 12v battery
• 12v ignition
• 5v sensor ref
• A/c on signal in
• A10
• A11
• A12
• Air conditioning system
• Air switch solenoid
• Air switch solenoid (5.0l & 5.7l- pickup only) (right front of engine)
• Anti-lock brake system
• B10
• B11
• B12
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• C216
• Coolant temp sens sig
• Crank fuse 5a
• Crank signal
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Data link connector (under left side of i/p)
• Distributor ref hi
• Distributor ref lo
• Dlc diagnostic test
• Dlc serial data
• Ecm-ign fuse 10a
• Egr solenoid
• Engine control module (under right side of i/p)
• Exhaust gas recirculation solenoid (5.0l & 5.7l ld only) (left rear top of engine)
• Fuel pump relay ctrl
• Fuel pump signal input
• Fuse block
• Gauges fuse 20a
• Hot at all times
• Hot in run, bulb test, or start
• Hot in start
• Iac coil a hi
• Iac coil a lo
• Iac coil b hi
• Iac coil b lo
• Ic bypass
• Idle air control unit (right rear of tbi unit)
• Ignition control (ic)
• Inj fuse 10a
• Injector 1 driver
• Injector 2 driver
• Instrument cluster
• Map 5v sensor ground
• Map sensor signal
• Mil indicator ctrl
• Oxygen sensor (left side exhaust manifold)
• Oxygen sensor ground
• Oxygen sensor signal
• Red
• Sensor return ground
• Service engine soon indicator
• Spark retard signal
• System ground
• Tan
• Throttle body fuel injector #1 (top of throttle body unit)
• Throttle body fuel injector #2 (top of throttle body unit)
• Tp sensor signal
• Up- shift lamp
• Upshift lamp ctrl
• Vss buffer signal

5.7L (VIN K), Engine Performance Wiring Diagrams, M/T (2 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 5.7L (VIN K), Engine Performance Wiring Diagrams, M/T (2 of 2) for GMC Cab & Chassis C2500 1994:

• (center rear
• Accy
• Bulb test
• C12
• C14
• C15
• Distributor
• Egr elec- tronic vacuum regulator solenoid (5.7l hd only) (right top of engine)
• Engine coolant temperature sensor (right top front of engine)
• Fuel pump and sender
• Fuel pump in-line fuse 20a
• Fuel pump oil pressure switch (left rear of engine, near exhaust manifold)
• Fuel pump relay (right rear of engine compartment, near battery junction block)
• G110 (left top front of engine)
• G125 (top front center of engine)
• Hot at all times
• Ignition coil (center rear of engine)
• Ignition switch
• Instrument cluster
• Knock sensor (right side of engine, below exhaust manifold)
• Knock sensor module (above right side rocker cover)
• Lock
• Manifold absolute pressure sensor (right rear top of engine)
• Nca
• Of engine)
• Off
• Oil press in
• Pnk
• Red
• Run
• Start
• Tach in
• Tachometer test lead
• Tan
• Throttle position sensor (right side of throttle body)
• Vehicle speed sensor (left rear side of transmission)
• Vehicle speed sensor buffer (under right side end of i/p)
• Vss in

6.5L

6.5L (VIN F), Engine Performance Wiring Diagrams, 4L60E A/T (1 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 6.5L (VIN F), Engine Performance Wiring Diagrams, 4L60E A/T (1 of 2) for GMC Cab & Chassis C2500 1994:

• 1-2 shift sol
• 1-2 shift sol ctrl
• 2-3 shift sol
• 2-3 shift sol ctrl
• 3-2 shift sol
• 4 wheel drive low switch
• 4wd fuse 25a
• 5v ref
• A range mode selector
• Accelerator pedal position (app) module (top of accelerator bracket)
• Anti-lock brakes system
• App 1 sens 5v ref
• App 1 sens gnd
• App 1 sensor
• App 2 sens gnd
• App 2 sensor
• App 3 sens 5v ref
• App 3 sens gnd
• App 3 sensor
• App sens 1 sig
• App sens 2 sig
• B/h
• Battery feed
• Boost sig
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• Ckp sig
• Closure sig
• Crk fuse 5a
• Cruise control system
• Cruise on/off sig
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Data link connector (under left side of i/p)
• E10
• E11
• E12
• E13
• E14
• E15
• E16
• Ect sig
• Egr ctrl/baro sig
• Egr sol ctrl
• Electronic 4-speed automatic overdrive transmission
• Eng shut-off ctrl
• Engine coolant temperature (ect) sensor (right side of engine)
• Engine shut- off solenoid (top front of engine)
• F/sol fuse 20a
• F10
• F11
• F12
• F13
• F14
• F15
• F16
• Fuel inj ctrl
• Fuel inj sig
• Fuel solenoid (top front of engine)
• Fuel solenoid driver (top front of engine)
• Fuse block
• Fwd low sw
• G117 (top right rear of engine)
• Glow plug rly ctrl
• Hi resolution sig
• Hot at all times
• Hot in crank
• Hot in run
• Hot in start or run
• Mil
• Optical sens 5v ref
• Optical sens cam sig
• Optical sens gnd
• Optical sensor and fuel temper- ature sensor (top front of engine)
• Pnk
• Powertrain control module (pcm) (under right end of i/p)
• Press ctrl sol
• Press ctrl sol (lo)
• Pressure control sol
• Range signal a
• Range signal b
• Range signal c
• Red
• Resume/accel sig
• Sensor gnd
• Serial data
• Set/coast sig
• Speed sensor (left rear side of transmission)
• System gnd
• Tan
• Tcc brake sw
• Tcc sol
• Tcc sol ctrl
• Trans fluid temp (tft) sensor
• Trans fluid temp sig
• Trans fuse 10a
• Trans input spd (hi)
• Trans input spd sig
• Trans output
• Trans output spd sig
• Transmission input speed sensor
• Turbo only
• Vehicle speed sensor buffer (under right end of i/p)
• Vin p only
• Vss
• Vss input
• Vss output

6.5L (VIN F), Engine Performance Wiring Diagrams, 4L60E A/T (2 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 6.5L (VIN F), Engine Performance Wiring Diagrams, 4L60E A/T (2 of 2) for GMC Cab & Chassis C2500 1994:

• "service engine soon" lamp
• "service throttle" lamp
• (left rear top of engine)
• (rear of right cylinder head)
• (turbo only)
• (under left side of i/p, near dlc)
• (upper rear of engine)
• 2-3 shift sol ctrl
• 20a
• A/c sig
• A10
• A11
• A12
• Air conditioning system
• App 2 sens 5v ref
• App 3 sens sig
• B/h
• B10
• B11
• B12
• Baro sensor (vin f) (upper left side of cowl)
• C red
• C203
• Crankshaft position sensor (top front of engine, inside
• Cruise ctrl brake sig
• Diagnostic request
• Ecm-ign fuse 10a
• Egr control pressure/ baro sensor (vin p & s) (upper left side of cowl)
• Egr solenoid (vin p) (left rear top of engine)
• Egr vent sol ctrl
• Egr vent solenoid (vin p & s)
• Fuel heater (top rear of engine)
• Fuel pump in-line fuse
• Fuel pump oil pressure switch
• Fuel pump relay (right upper cowl)
• Fuel pump/sender (in fuel tank)
• Fuel temp sig
• Fuse block
• Fusible link (12ga-
• Fusible links
• G117
• G117 (top right rear of engine)
• G206
• Gauges fuse 20a
• Glo plug fuse 5a
• Glow plug control relay (right rear top of engine)
• Glow plug sig
• Hot at all times
• Hot in run, bulb test or start
• Hot in start or run
• Iat sig
• Ignition feed
• Injection pump)
• Injection timing stepper (its) motor (top front of engine)
• Instrument cluster
• Instrument clusters system
• Intake air temperature (iat) sensor (at front of engine)
• Its coil 1 hi
• Its coil 1 lo
• Its coil 2 hi
• Its coil 2 lo
• Left bank glow plugs
• Manifold absolute pressure sensor (turbo only) (left rear engine compt, at cowl)
• Powertrain control module (pcm) (under right end of i/p)
• Red
• Right bank glow plugs
• Sol fuse 5a
• Stop fuse 15a
• Tan
• Tcc/ brake switch (on brake pedal support bracket)
• Vin p only
• Wait lamp
• Wastegate sol ctrl
• Wastegate solenoid (turbo only) (left rear top of engine)

6.5L (VIN F), Engine Performance Wiring Diagrams, 4L80E A/T (1 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 6.5L (VIN F), Engine Performance Wiring Diagrams, 4L80E A/T (1 of 2) for GMC Cab & Chassis C2500 1994:

• 1-2 shift sol
• 1-2 shift sol ctrl
• 2-3 shift sol
• 2-3 shift sol ctrl
• 4 wheel drive low switch
• 4wd fuse 25a
• 5v ref
• A range mode selector
• Accelerator pedal position (app) module (top of accelerator bracket)
• Anti-lock brakes system
• App 1 sens 5v ref
• App 1 sens gnd
• App 1 sensor
• App 2 sens gnd
• App 2 sensor
• App 3 sens 5v ref
• App 3 sens gnd
• App 3 sensor
• App sens 1 sig
• App sens 2 sig
• B/h
• Battery feed
• Boost sig
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• Ckp sig
• Closure sig
• Crk fuse 5a
• Cruise control system
• Cruise on/off sig
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Data link connector (under left side of i/p)
• E10
• E11
• E12
• E13
• E14
• E15
• E16
• Ect sig
• Egr ctrl/baro sig
• Egr sol ctrl
• Electronic 4-speed automatic overdrive transmission
• Eng shut-off ctrl
• Engine coolant temperature (ect) sensor (right side of engine)
• Engine shut- off solenoid (top front of engine)
• F/sol fuse 20a
• F10
• F11
• F12
• F13
• F14
• F15
• F16
• Fuel inj ctrl
• Fuel inj sig
• Fuel solenoid (top front of engine)
• Fuel solenoid driver (top front of engine)
• Fuse block
• Fwd low sw
• G117 (top right rear of engine)
• Glow plug rly ctrl
• Hi resolution sig
• Hot at all times
• Hot in crank
• Hot in run
• Hot in start or run
• Mil
• Optical sens 5v ref
• Optical sens cam sig
• Optical sens gnd
• Optical sensor and fuel temper- ature sensor (top front of engine)
• Pnk
• Powertrain control module (pcm) (under right end of i/p)
• Press ctrl sol
• Press ctrl sol (lo)
• Pressure control sol
• Range signal a
• Range signal b
• Range signal c
• Red
• Resume/accel sig
• Sensor gnd
• Serial data
• Set/coast sig
• Speed sensor (left rear side of transmission)
• System gnd
• Tan
• Tcc brake sw
• Tcc sol
• Tcc sol ctrl (pwm)
• Trans fluid temp (tft) sensor
• Trans fluid temp sig
• Trans fuse 10a
• Trans input spd (hi)
• Trans input spd sig
• Trans output
• Trans output spd sig
• Transmission input speed sensor
• Turbo only
• Vehicle speed sensor buffer (under right end of i/p)
• Vin p only
• Vss
• Vss input
• Vss output

6.5L (VIN F), Engine Performance Wiring Diagrams, 4L80E A/T (2 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 6.5L (VIN F), Engine Performance Wiring Diagrams, 4L80E A/T (2 of 2) for GMC Cab & Chassis C2500 1994:

• "service engine soon" lamp
• "service throttle" lamp
• (left rear top of engine)
• (rear of right cylinder head)
• (turbo only)
• (under left side of i/p, near dlc)
• (upper rear of engine)
• 20a
• A/c sig
• A10
• A11
• A12
• Air conditioning system
• App 2 sens 5v ref
• App 3 sens sig
• B/h
• B10
• B11
• B12
• Baro sensor (vin f) (upper left side of cowl)
• C red
• C203
• Crankshaft position sensor (top front of engine, inside
• Cruise ctrl brake sig
• Diagnostic request
• Ecm-ign fuse 10a
• Egr control pressure/ baro sensor (vin p & s) (upper left side of cowl)
• Egr solenoid (vin p) (left rear top of engine)
• Egr vent sol ctrl
• Egr vent solenoid (vin p & s)
• Fuel heater (top rear of engine)
• Fuel pump in-line fuse
• Fuel pump oil pressure switch
• Fuel pump relay (right upper cowl)
• Fuel pump/sender (in fuel tank)
• Fuel temp sig
• Fuse block
• Fusible link (12ga-
• Fusible links
• G117
• G117 (top right rear of engine)
• G206
• Gauges fuse 20a
• Glo plug fuse 5a
• Glow plug control relay (right rear top of engine)
• Glow plug sig
• Hot at all times
• Hot in run, bulb test or start
• Hot in start or run
• Iat sig
• Ignition feed
• Injection pump)
• Injection timing stepper (its) motor (top front of engine)
• Instrument cluster
• Instrument clusters system
• Intake air temperature (iat) sensor (at front of engine)
• Its coil 1 hi
• Its coil 1 lo
• Its coil 2 hi
• Its coil 2 lo
• Left bank glow plugs
• Manifold absolute pressure sensor (turbo only) (left rear engine compt, at cowl)
• Powertrain control module (pcm) (under right end of i/p)
• Red
• Right bank glow plugs
• Sol fuse 5a
• Stop fuse 15a
• Tan
• Tcc/ brake switch (on brake pedal support bracket)
• Vin p only
• Wait lamp
• Wastegate sol ctrl
• Wastegate solenoid (turbo only) (left rear top of engine)

6.5L (VIN P), Engine Performance Wiring Diagrams, 4L60E A/T (1 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 6.5L (VIN P), Engine Performance Wiring Diagrams, 4L60E A/T (1 of 2) for GMC Cab & Chassis C2500 1994:

• 1-2 shift sol
• 1-2 shift sol ctrl
• 2-3 shift sol
• 2-3 shift sol ctrl
• 3-2 shift sol
• 4 wheel drive low switch
• 4wd fuse 25a
• 5v ref
• A range mode selector
• Accelerator pedal position (app) module (top of accelerator bracket)
• Anti-lock brakes system
• App 1 sens 5v ref
• App 1 sens gnd
• App 1 sensor
• App 2 sens gnd
• App 2 sensor
• App 3 sens 5v ref
• App 3 sens gnd
• App 3 sensor
• App sens 1 sig
• App sens 2 sig
• B/h
• Battery feed
• Boost sig
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• Ckp sig
• Closure sig
• Crk fuse 5a
• Cruise control system
• Cruise on/off sig
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Data link connector (under left side of i/p)
• E10
• E11
• E12
• E13
• E14
• E15
• E16
• Ect sig
• Egr ctrl/baro sig
• Egr sol ctrl
• Electronic 4-speed automatic overdrive transmission
• Eng shut-off ctrl
• Engine coolant temperature (ect) sensor (right side of engine)
• Engine shut- off solenoid (top front of engine)
• F/sol fuse 20a
• F10
• F11
• F12
• F13
• F14
• F15
• F16
• Fuel inj ctrl
• Fuel inj sig
• Fuel solenoid (top front of engine)
• Fuel solenoid driver (top front of engine)
• Fuse block
• Fwd low sw
• G117 (top right rear of engine)
• Glow plug rly ctrl
• Hi resolution sig
• Hot at all times
• Hot in crank
• Hot in run
• Hot in start or run
• Mil
• Optical sens 5v ref
• Optical sens cam sig
• Optical sens gnd
• Optical sensor and fuel temper- ature sensor (top front of engine)
• Pnk
• Powertrain control module (pcm) (under right end of i/p)
• Press ctrl sol
• Press ctrl sol (lo)
• Pressure control sol
• Range signal a
• Range signal b
• Range signal c
• Red
• Resume/accel sig
• Sensor gnd
• Serial data
• Set/coast sig
• Speed sensor (left rear side of transmission)
• System gnd
• Tan
• Tcc brake sw
• Tcc sol
• Tcc sol ctrl
• Trans fluid temp (tft) sensor
• Trans fluid temp sig
• Trans fuse 10a
• Trans input spd (hi)
• Trans input spd sig
• Trans output
• Trans output spd sig
• Transmission input speed sensor
• Turbo only
• Vehicle speed sensor buffer (under right end of i/p)
• Vin p only
• Vss
• Vss input
• Vss output

6.5L (VIN P), Engine Performance Wiring Diagrams, 4L60E A/T (2 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 6.5L (VIN P), Engine Performance Wiring Diagrams, 4L60E A/T (2 of 2) for GMC Cab & Chassis C2500 1994:

• "service engine soon" lamp
• "service throttle" lamp
• (left rear top of engine)
• (rear of right cylinder head)
• (turbo only)
• (under left side of i/p, near dlc)
• (upper rear of engine)
• 2-3 shift sol ctrl
• 20a
• A/c sig
• A10
• A11
• A12
• Air conditioning system
• App 2 sens 5v ref
• App 3 sens sig
• B/h
• B10
• B11
• B12
• Baro sensor (vin f) (upper left side of cowl)
• C red
• C203
• Crankshaft position sensor (top front of engine, inside
• Cruise ctrl brake sig
• Diagnostic request
• Ecm-ign fuse 10a
• Egr control pressure/ baro sensor (vin p & s) (upper left side of cowl)
• Egr solenoid (vin p) (left rear top of engine)
• Egr vent sol ctrl
• Egr vent solenoid (vin p & s)
• Fuel heater (top rear of engine)
• Fuel pump in-line fuse
• Fuel pump oil pressure switch
• Fuel pump relay (right upper cowl)
• Fuel pump/sender (in fuel tank)
• Fuel temp sig
• Fuse block
• Fusible link (12ga-
• Fusible links
• G117
• G117 (top right rear of engine)
• G206
• Gauges fuse 20a
• Glo plug fuse 5a
• Glow plug control relay (right rear top of engine)
• Glow plug sig
• Hot at all times
• Hot in run, bulb test or start
• Hot in start or run
• Iat sig
• Ignition feed
• Injection pump)
• Injection timing stepper (its) motor (top front of engine)
• Instrument cluster
• Instrument clusters system
• Intake air temperature (iat) sensor (at front of engine)
• Its coil 1 hi
• Its coil 1 lo
• Its coil 2 hi
• Its coil 2 lo
• Left bank glow plugs
• Manifold absolute pressure sensor (turbo only) (left rear engine compt, at cowl)
• Powertrain control module (pcm) (under right end of i/p)
• Red
• Right bank glow plugs
• Sol fuse 5a
• Stop fuse 15a
• Tan
• Tcc/ brake switch (on brake pedal support bracket)
• Vin p only
• Wait lamp
• Wastegate sol ctrl
• Wastegate solenoid (turbo only) (left rear top of engine)

6.5L (VIN P), Engine Performance Wiring Diagrams, 4L80E A/T (1 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 6.5L (VIN P), Engine Performance Wiring Diagrams, 4L80E A/T (1 of 2) for GMC Cab & Chassis C2500 1994:

• 1-2 shift sol
• 1-2 shift sol ctrl
• 2-3 shift sol
• 2-3 shift sol ctrl
• 4 wheel drive low switch
• 4wd fuse 25a
• 5v ref
• A range mode selector
• Accelerator pedal position (app) module (top of accelerator bracket)
• Anti-lock brakes system
• App 1 sens 5v ref
• App 1 sens gnd
• App 1 sensor
• App 2 sens gnd
• App 2 sensor
• App 3 sens 5v ref
• App 3 sens gnd
• App 3 sensor
• App sens 1 sig
• App sens 2 sig
• B/h
• Battery feed
• Boost sig
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• Ckp sig
• Closure sig
• Crk fuse 5a
• Cruise control system
• Cruise on/off sig
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Data link connector (under left side of i/p)
• E10
• E11
• E12
• E13
• E14
• E15
• E16
• Ect sig
• Egr ctrl/baro sig
• Egr sol ctrl
• Electronic 4-speed automatic overdrive transmission
• Eng shut-off ctrl
• Engine coolant temperature (ect) sensor (right side of engine)
• Engine shut- off solenoid (top front of engine)
• F/sol fuse 20a
• F10
• F11
• F12
• F13
• F14
• F15
• F16
• Fuel inj ctrl
• Fuel inj sig
• Fuel solenoid (top front of engine)
• Fuel solenoid driver (top front of engine)
• Fuse block
• Fwd low sw
• G117 (top right rear of engine)
• Glow plug rly ctrl
• Hi resolution sig
• Hot at all times
• Hot in crank
• Hot in run
• Hot in start or run
• Mil
• Optical sens 5v ref
• Optical sens cam sig
• Optical sens gnd
• Optical sensor and fuel temper- ature sensor (top front of engine)
• Pnk
• Powertrain control module (pcm) (under right end of i/p)
• Press ctrl sol
• Press ctrl sol (lo)
• Pressure control sol
• Range signal a
• Range signal b
• Range signal c
• Red
• Resume/accel sig
• Sensor gnd
• Serial data
• Set/coast sig
• Speed sensor (left rear side of transmission)
• System gnd
• Tan
• Tcc brake sw
• Tcc sol
• Tcc sol ctrl (pwm)
• Trans fluid temp (tft) sensor
• Trans fluid temp sig
• Trans fuse 10a
• Trans input spd (hi)
• Trans input spd sig
• Trans output
• Trans output spd sig
• Transmission input speed sensor
• Turbo only
• Vehicle speed sensor buffer (under right end of i/p)
• Vin p only
• Vss
• Vss input
• Vss output

6.5L (VIN P), Engine Performance Wiring Diagrams, 4L80E A/T (2 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 6.5L (VIN P), Engine Performance Wiring Diagrams, 4L80E A/T (2 of 2) for GMC Cab & Chassis C2500 1994:

• "service engine soon" lamp
• "service throttle" lamp
• (left rear top of engine)
• (rear of right cylinder head)
• (turbo only)
• (under left side of i/p, near dlc)
• (upper rear of engine)
• 20a
• A/c sig
• A10
• A11
• A12
• Air conditioning system
• App 2 sens 5v ref
• App 3 sens sig
• B/h
• B10
• B11
• B12
• Baro sensor (vin f) (upper left side of cowl)
• C red
• C203
• Crankshaft position sensor (top front of engine, inside
• Cruise ctrl brake sig
• Diagnostic request
• Ecm-ign fuse 10a
• Egr control pressure/ baro sensor (vin p & s) (upper left side of cowl)
• Egr solenoid (vin p) (left rear top of engine)
• Egr vent sol ctrl
• Egr vent solenoid (vin p & s)
• Fuel heater (top rear of engine)
• Fuel pump in-line fuse
• Fuel pump oil pressure switch
• Fuel pump relay (right upper cowl)
• Fuel pump/sender (in fuel tank)
• Fuel temp sig
• Fuse block
• Fusible link (12ga-
• Fusible links
• G117
• G117 (top right rear of engine)
• G206
• Gauges fuse 20a
• Glo plug fuse 5a
• Glow plug control relay (right rear top of engine)
• Glow plug sig
• Hot at all times
• Hot in run, bulb test or start
• Hot in start or run
• Iat sig
• Ignition feed
• Injection pump)
• Injection timing stepper (its) motor (top front of engine)
• Instrument cluster
• Instrument clusters system
• Intake air temperature (iat) sensor (at front of engine)
• Its coil 1 hi
• Its coil 1 lo
• Its coil 2 hi
• Its coil 2 lo
• Left bank glow plugs
• Manifold absolute pressure sensor (turbo only) (left rear engine compt, at cowl)
• Powertrain control module (pcm) (under right end of i/p)
• Red
• Right bank glow plugs
• Sol fuse 5a
• Stop fuse 15a
• Tan
• Tcc/ brake switch (on brake pedal support bracket)
• Vin p only
• Wait lamp
• Wastegate sol ctrl
• Wastegate solenoid (turbo only) (left rear top of engine)

6.5L (VIN P), Engine Performance Wiring Diagrams, M/T (1 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 6.5L (VIN P), Engine Performance Wiring Diagrams, M/T (1 of 2) for GMC Cab & Chassis C2500 1994:

• 4 wheel drive low switch
• 4wd fuse 25a
• 4wd low sw
• 5v ref
• Accelerator pedal position (app) module (top of accelerator bracket)
• Anti-lock brakes system
• App 1 sens 5v ref
• App 1 sens gnd
• App 1 sensor
• App 2 sens gnd
• App 2 sensor
• App 3 sens 5v ref
• App 3 sens gnd
• App 3 sensor
• App sens 1 sig
• App sens 2 sig
• Battery feed
• Boost sig
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• Ckp sig
• Closure gnd
• Clutch pedal position switch
• Conven- ience center
• Crk fuse 5a
• Cruise control system
• Cruise on/off sig
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Data link connector (under left side of i/p)
• E10
• E11
• E12
• E13
• E14
• E15
• E16
• Ect sig
• Egr ctrl/baro sig
• Egr sol ctrl
• Eng shut-off ctrl
• Engine coolant temperature (ect) sensor (right side of engine)
• Engine shut- off solenoid (top front of engine)
• F/sol fuse 20a
• F10
• F11
• F12
• F13
• F14
• F15
• F16
• Fuel inj ctrl
• Fuel inj sig
• Fuel solenoid (top front of engine)
• Fuel solenoid driver (top front of engine)
• Fuse block
• G117 (top right rear of engine)
• Glow plug rly ctrl
• Hi resolution sig
• Hot at all times
• Hot in crank
• Hot in run
• Hot in start
• Mil
• Optical sens 5v ref
• Optical sens cam sig
• Optical sens gnd
• Optical sensor and fuel temper- ature sensor (top front of engine)
• Or run
• Pnk
• Powertrain control module (pcm) (under right end of i/p)
• Red
• Resume/accel sig
• Sensor gnd
• Serial data
• Set/coast sig
• Speed sensor (left rear side of transmission)
• System gnd
• Tan
• Tcc brake sw
• Trans fluid temp sig
• Trans output
• Trans output spd sig
• Vehicle speed sensor buffer (under right end of i/p)
• Vss
• Vss input
• Vss output

6.5L (VIN P), Engine Performance Wiring Diagrams, M/T (2 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 6.5L (VIN P), Engine Performance Wiring Diagrams, M/T (2 of 2) for GMC Cab & Chassis C2500 1994:

• "service throttle" lamp
• 'service engine soon' lamp
• 'service throttle' lamp
• 'wait' lamp
• (upper rear of engine)
• 20a
• A/c sig
• A10
• A11
• A12
• Air cond- itioning system
• App 2 sens 5v ref
• App 3 sens sig
• B/h
• B10
• B11
• B12
• Baro sensor (vin f only) (upper left
• C red
• C203
• Crankshaft position sensor (top front of engine, inside
• Cruise ctrl brake sig
• Diagnostic request
• Ecm-ign fuse 10a
• Egr control pressure/ baro sensor (vin p & s) (upper left side of cowl)
• Egr solenoid (vin p only) (left rear top of engine)
• Egr vent sol ctrl
• Egr vent solenoid (vin p & s) (left rear top of engine)
• Fuel heater (top rear of engine)
• Fuel pump in-line fuse
• Fuel pump oil pressure switch
• Fuel pump relay (right side of safety wall)
• Fuel pump/sender (in fuel tank)
• Fuel temp sig
• Fuse block
• Fusible link (12ga-
• Fusible links
• G117 (rear of right cylinder head)
• G117 (top right rear of engine)
• G206 (under left side of i/p, near dlc)
• Gauges fuse 20a
• Glo plug fuse 5a
• Glow plug control relay (right rear top of engine)
• Glow plug sig
• Hot at all times
• Hot in run, bulb test or start
• Hot in start or run
• Iat sig
• Ignition feed
• Injection pump)
• Injection timing stepper (its) motor (top front of engine)
• Instrument cluster
• Instrument clusters system
• Intake air temperature (iat) sensor (at front of engine)
• Its coil 1 hi
• Its coil 1 lo
• Its coil 2 hi
• Its coil 2 lo
• Left bank glow plugs
• Manifold absolute pressure sensor (vin f & s) (left rear engine compt, at cowl)
• Powertrain control module (pcm) (under right end of i/p)
• Red
• Right bank glow plugs
• Side of cowl)
• Sol fuse 5a
• Stop fuse 15a
• Tan
• Tcc/ brake switch (on brake pedal support bracket)
• Wastegate sol ctrl
• Wastegate solenoid (vin f only) (left rear top of engine)

6.5L (VIN S), Engine Performance Wiring Diagrams, 4L60E A/T (1 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 6.5L (VIN S), Engine Performance Wiring Diagrams, 4L60E A/T (1 of 2) for GMC Cab & Chassis C2500 1994:

• 1-2 shift sol
• 1-2 shift sol ctrl
• 2-3 shift sol
• 2-3 shift sol ctrl
• 3-2 shift sol
• 4 wheel drive low switch
• 4wd fuse 25a
• 5v ref
• A range mode selector
• Accelerator pedal position (app) module (top of accelerator bracket)
• Anti-lock brakes system
• App 1 sens 5v ref
• App 1 sens gnd
• App 1 sensor
• App 2 sens gnd
• App 2 sensor
• App 3 sens 5v ref
• App 3 sens gnd
• App 3 sensor
• App sens 1 sig
• App sens 2 sig
• B/h
• Battery feed
• Boost sig
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• Ckp sig
• Closure sig
• Crk fuse 5a
• Cruise control system
• Cruise on/off sig
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Data link connector (under left side of i/p)
• E10
• E11
• E12
• E13
• E14
• E15
• E16
• Ect sig
• Egr ctrl/baro sig
• Egr sol ctrl
• Electronic 4-speed automatic overdrive transmission
• Eng shut-off ctrl
• Engine coolant temperature (ect) sensor (right side of engine)
• Engine shut- off solenoid (top front of engine)
• F/sol fuse 20a
• F10
• F11
• F12
• F13
• F14
• F15
• F16
• Fuel inj ctrl
• Fuel inj sig
• Fuel solenoid (top front of engine)
• Fuel solenoid driver (top front of engine)
• Fuse block
• Fwd low sw
• G117 (top right rear of engine)
• Glow plug rly ctrl
• Hi resolution sig
• Hot at all times
• Hot in crank
• Hot in run
• Hot in start or run
• Mil
• Optical sens 5v ref
• Optical sens cam sig
• Optical sens gnd
• Optical sensor and fuel temper- ature sensor (top front of engine)
• Pnk
• Powertrain control module (pcm) (under right end of i/p)
• Press ctrl sol
• Press ctrl sol (lo)
• Pressure control sol
• Range signal a
• Range signal b
• Range signal c
• Red
• Resume/accel sig
• Sensor gnd
• Serial data
• Set/coast sig
• Speed sensor (left rear side of transmission)
• System gnd
• Tan
• Tcc brake sw
• Tcc sol
• Tcc sol ctrl
• Trans fluid temp (tft) sensor
• Trans fluid temp sig
• Trans fuse 10a
• Trans input spd (hi)
• Trans input spd sig
• Trans output
• Trans output spd sig
• Transmission input speed sensor
• Turbo only
• Vehicle speed sensor buffer (under right end of i/p)
• Vin p only
• Vss
• Vss input
• Vss output

6.5L (VIN S), Engine Performance Wiring Diagrams, 4L60E A/T (2 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 6.5L (VIN S), Engine Performance Wiring Diagrams, 4L60E A/T (2 of 2) for GMC Cab & Chassis C2500 1994:

• "service engine soon" lamp
• "service throttle" lamp
• (left rear top of engine)
• (rear of right cylinder head)
• (turbo only)
• (under left side of i/p, near dlc)
• (upper rear of engine)
• 2-3 shift sol ctrl
• 20a
• A/c sig
• A10
• A11
• A12
• Air conditioning system
• App 2 sens 5v ref
• App 3 sens sig
• B/h
• B10
• B11
• B12
• Baro sensor (vin f) (upper left side of cowl)
• C red
• C203
• Crankshaft position sensor (top front of engine, inside
• Cruise ctrl brake sig
• Diagnostic request
• Ecm-ign fuse 10a
• Egr control pressure/ baro sensor (vin p & s) (upper left side of cowl)
• Egr solenoid (vin p) (left rear top of engine)
• Egr vent sol ctrl
• Egr vent solenoid (vin p & s)
• Fuel heater (top rear of engine)
• Fuel pump in-line fuse
• Fuel pump oil pressure switch
• Fuel pump relay (right upper cowl)
• Fuel pump/sender (in fuel tank)
• Fuel temp sig
• Fuse block
• Fusible link (12ga-
• Fusible links
• G117
• G117 (top right rear of engine)
• G206
• Gauges fuse 20a
• Glo plug fuse 5a
• Glow plug control relay (right rear top of engine)
• Glow plug sig
• Hot at all times
• Hot in run, bulb test or start
• Hot in start or run
• Iat sig
• Ignition feed
• Injection pump)
• Injection timing stepper (its) motor (top front of engine)
• Instrument cluster
• Instrument clusters system
• Intake air temperature (iat) sensor (at front of engine)
• Its coil 1 hi
• Its coil 1 lo
• Its coil 2 hi
• Its coil 2 lo
• Left bank glow plugs
• Manifold absolute pressure sensor (turbo only) (left rear engine compt, at cowl)
• Powertrain control module (pcm) (under right end of i/p)
• Red
• Right bank glow plugs
• Sol fuse 5a
• Stop fuse 15a
• Tan
• Tcc/ brake switch (on brake pedal support bracket)
• Vin p only
• Wait lamp
• Wastegate sol ctrl
• Wastegate solenoid (turbo only) (left rear top of engine)

6.5L (VIN S), Engine Performance Wiring Diagrams, 4L80E A/T (1 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 6.5L (VIN S), Engine Performance Wiring Diagrams, 4L80E A/T (1 of 2) for GMC Cab & Chassis C2500 1994:

• 1-2 shift sol
• 1-2 shift sol ctrl
• 2-3 shift sol
• 2-3 shift sol ctrl
• 4 wheel drive low switch
• 4wd fuse 25a
• 5v ref
• A range mode selector
• Accelerator pedal position (app) module (top of accelerator bracket)
• Anti-lock brakes system
• App 1 sens 5v ref
• App 1 sens gnd
• App 1 sensor
• App 2 sens gnd
• App 2 sensor
• App 3 sens 5v ref
• App 3 sens gnd
• App 3 sensor
• App sens 1 sig
• App sens 2 sig
• B/h
• Battery feed
• Boost sig
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• Ckp sig
• Closure sig
• Crk fuse 5a
• Cruise control system
• Cruise on/off sig
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Data link connector (under left side of i/p)
• E10
• E11
• E12
• E13
• E14
• E15
• E16
• Ect sig
• Egr ctrl/baro sig
• Egr sol ctrl
• Electronic 4-speed automatic overdrive transmission
• Eng shut-off ctrl
• Engine coolant temperature (ect) sensor (right side of engine)
• Engine shut- off solenoid (top front of engine)
• F/sol fuse 20a
• F10
• F11
• F12
• F13
• F14
• F15
• F16
• Fuel inj ctrl
• Fuel inj sig
• Fuel solenoid (top front of engine)
• Fuel solenoid driver (top front of engine)
• Fuse block
• Fwd low sw
• G117 (top right rear of engine)
• Glow plug rly ctrl
• Hi resolution sig
• Hot at all times
• Hot in crank
• Hot in run
• Hot in start or run
• Mil
• Optical sens 5v ref
• Optical sens cam sig
• Optical sens gnd
• Optical sensor and fuel temper- ature sensor (top front of engine)
• Pnk
• Powertrain control module (pcm) (under right end of i/p)
• Press ctrl sol
• Press ctrl sol (lo)
• Pressure control sol
• Range signal a
• Range signal b
• Range signal c
• Red
• Resume/accel sig
• Sensor gnd
• Serial data
• Set/coast sig
• Speed sensor (left rear side of transmission)
• System gnd
• Tan
• Tcc brake sw
• Tcc sol
• Tcc sol ctrl (pwm)
• Trans fluid temp (tft) sensor
• Trans fluid temp sig
• Trans fuse 10a
• Trans input spd (hi)
• Trans input spd sig
• Trans output
• Trans output spd sig
• Transmission input speed sensor
• Turbo only
• Vehicle speed sensor buffer (under right end of i/p)
• Vin p only
• Vss
• Vss input
• Vss output

6.5L (VIN S), Engine Performance Wiring Diagrams, 4L80E A/T (2 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 6.5L (VIN S), Engine Performance Wiring Diagrams, 4L80E A/T (2 of 2) for GMC Cab & Chassis C2500 1994:

• "service engine soon" lamp
• "service throttle" lamp
• (left rear top of engine)
• (rear of right cylinder head)
• (turbo only)
• (under left side of i/p, near dlc)
• (upper rear of engine)
• 20a
• A/c sig
• A10
• A11
• A12
• Air conditioning system
• App 2 sens 5v ref
• App 3 sens sig
• B/h
• B10
• B11
• B12
• Baro sensor (vin f) (upper left side of cowl)
• C red
• C203
• Crankshaft position sensor (top front of engine, inside
• Cruise ctrl brake sig
• Diagnostic request
• Ecm-ign fuse 10a
• Egr control pressure/ baro sensor (vin p & s) (upper left side of cowl)
• Egr solenoid (vin p) (left rear top of engine)
• Egr vent sol ctrl
• Egr vent solenoid (vin p & s)
• Fuel heater (top rear of engine)
• Fuel pump in-line fuse
• Fuel pump oil pressure switch
• Fuel pump relay (right upper cowl)
• Fuel pump/sender (in fuel tank)
• Fuel temp sig
• Fuse block
• Fusible link (12ga-
• Fusible links
• G117
• G117 (top right rear of engine)
• G206
• Gauges fuse 20a
• Glo plug fuse 5a
• Glow plug control relay (right rear top of engine)
• Glow plug sig
• Hot at all times
• Hot in run, bulb test or start
• Hot in start or run
• Iat sig
• Ignition feed
• Injection pump)
• Injection timing stepper (its) motor (top front of engine)
• Instrument cluster
• Instrument clusters system
• Intake air temperature (iat) sensor (at front of engine)
• Its coil 1 hi
• Its coil 1 lo
• Its coil 2 hi
• Its coil 2 lo
• Left bank glow plugs
• Manifold absolute pressure sensor (turbo only) (left rear engine compt, at cowl)
• Powertrain control module (pcm) (under right end of i/p)
• Red
• Right bank glow plugs
• Sol fuse 5a
• Stop fuse 15a
• Tan
• Tcc/ brake switch (on brake pedal support bracket)
• Vin p only
• Wait lamp
• Wastegate sol ctrl
• Wastegate solenoid (turbo only) (left rear top of engine)

6.5L (VIN S), Engine Performance Wiring Diagrams, M/T (1 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 6.5L (VIN S), Engine Performance Wiring Diagrams, M/T (1 of 2) for GMC Cab & Chassis C2500 1994:

• 4 wheel drive low switch
• 4wd fuse 25a
• 4wd low sw
• 5v ref
• Accelerator pedal position (app) module (top of accelerator bracket)
• Anti-lock brakes system
• App 1 sens 5v ref
• App 1 sens gnd
• App 1 sensor
• App 2 sens gnd
• App 2 sensor
• App 3 sens 5v ref
• App 3 sens gnd
• App 3 sensor
• App sens 1 sig
• App sens 2 sig
• Battery feed
• Boost sig
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• Ckp sig
• Closure gnd
• Clutch pedal position switch
• Conven- ience center
• Crk fuse 5a
• Cruise control system
• Cruise on/off sig
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Data link connector (under left side of i/p)
• E10
• E11
• E12
• E13
• E14
• E15
• E16
• Ect sig
• Egr ctrl/baro sig
• Egr sol ctrl
• Eng shut-off ctrl
• Engine coolant temperature (ect) sensor (right side of engine)
• Engine shut- off solenoid (top front of engine)
• F/sol fuse 20a
• F10
• F11
• F12
• F13
• F14
• F15
• F16
• Fuel inj ctrl
• Fuel inj sig
• Fuel solenoid (top front of engine)
• Fuel solenoid driver (top front of engine)
• Fuse block
• G117 (top right rear of engine)
• Glow plug rly ctrl
• Hi resolution sig
• Hot at all times
• Hot in crank
• Hot in run
• Hot in start
• Mil
• Optical sens 5v ref
• Optical sens cam sig
• Optical sens gnd
• Optical sensor and fuel temper- ature sensor (top front of engine)
• Or run
• Pnk
• Powertrain control module (pcm) (under right end of i/p)
• Red
• Resume/accel sig
• Sensor gnd
• Serial data
• Set/coast sig
• Speed sensor (left rear side of transmission)
• System gnd
• Tan
• Tcc brake sw
• Trans fluid temp sig
• Trans output
• Trans output spd sig
• Vehicle speed sensor buffer (under right end of i/p)
• Vss
• Vss input
• Vss output

6.5L (VIN S), Engine Performance Wiring Diagrams, M/T (2 of 2) for GMC Cab & Chassis C2500 1994

List of elements for 6.5L (VIN S), Engine Performance Wiring Diagrams, M/T (2 of 2) for GMC Cab & Chassis C2500 1994:

• "service throttle" lamp
• 'service engine soon' lamp
• 'service throttle' lamp
• 'wait' lamp
• (upper rear of engine)
• 20a
• A/c sig
• A10
• A11
• A12
• Air cond- itioning system
• App 2 sens 5v ref
• App 3 sens sig
• B/h
• B10
• B11
• B12
• Baro sensor (vin f only) (upper left
• C red
• C203
• Crankshaft position sensor (top front of engine, inside
• Cruise ctrl brake sig
• Diagnostic request
• Ecm-ign fuse 10a
• Egr control pressure/ baro sensor (vin p & s) (upper left side of cowl)
• Egr solenoid (vin p only) (left rear top of engine)
• Egr vent sol ctrl
• Egr vent solenoid (vin p & s) (left rear top of engine)
• Fuel heater (top rear of engine)
• Fuel pump in-line fuse
• Fuel pump oil pressure switch
• Fuel pump relay (right side of safety wall)
• Fuel pump/sender (in fuel tank)
• Fuel temp sig
• Fuse block
• Fusible link (12ga-
• Fusible links
• G117 (rear of right cylinder head)
• G117 (top right rear of engine)
• G206 (under left side of i/p, near dlc)
• Gauges fuse 20a
• Glo plug fuse 5a
• Glow plug control relay (right rear top of engine)
• Glow plug sig
• Hot at all times
• Hot in run, bulb test or start
• Hot in start or run
• Iat sig
• Ignition feed
• Injection pump)
• Injection timing stepper (its) motor (top front of engine)
• Instrument cluster
• Instrument clusters system
• Intake air temperature (iat) sensor (at front of engine)
• Its coil 1 hi
• Its coil 1 lo
• Its coil 2 hi
• Its coil 2 lo
• Left bank glow plugs
• Manifold absolute pressure sensor (vin f & s) (left rear engine compt, at cowl)
• Powertrain control module (pcm) (under right end of i/p)
• Red
• Right bank glow plugs
• Side of cowl)
• Sol fuse 5a
• Stop fuse 15a
• Tan
• Tcc/ brake switch (on brake pedal support bracket)
• Wastegate sol ctrl
• Wastegate solenoid (vin f only) (left rear top of engine)

7.4L

7.4L (VIN N), Engine Performance Wiring Diagrams, A/T (1 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 7.4L (VIN N), Engine Performance Wiring Diagrams, A/T (1 of 3) for GMC Cab & Chassis C2500 1994:

• (left top front
• 12v battery
• 12v ignition
• 5v return a
• 5v return b
• 5v sensor ref
• A/c on signal in
• A10
• A11
• A12
• A13
• A14
• A15
• A16
• Air condition- ing system
• B10
• B11
• B12
• B13
• B14
• B15
• B16
• Brake sw to pcm
• C215
• C218
• Coolant temp sensor
• Cruise control system
• Cruise ind reg grd
• Distributor ref hi
• Distributor ref lo
• Dlc
• Dlc serial data
• E10
• E11
• E12
• E13
• E14
• E15
• E16
• Ecm-ign fuse 10a
• Egr valve solenoid
• Elec fuel pump in
• Engine control module (under right side of i/p)
• Evap canister purge ctrl
• Evaporative canister purge solenoid (on engine)
• F10
• F11
• F12
• F13
• F14
• F15
• F16
• Fuel pump relay ctrl
• Fuse block
• G110
• G110 (left top front of engine)
• Hot in run
• Hot in run, bulb
• Idle air control unit (right rear of tbi unit)
• Ignition bypass
• Ignition control (ic)
• Inj fuse 10a
• Knock sensor in
• Linear egr position in
• Linear egr regulator solenoid valve (right top of engine)
• Lo side inj a
• Lo side inj b
• Map sensor in
• Mil indicator ctrl
• Of engine)
• Or start
• Oxygen sensor hi
• Oxygen sensor lo
• Pcm to trans temp sensor
• Pcm trans force mtr hi
• Pcm trans force mtr lo
• Pcm trans range a
• Pcm trans range b
• Pcm trans range c
• Pcm trans shift sol a
• Pcm trans shift sol b
• Pnk
• Red
• Stepper coil a hi
• Stepper coil a lo
• Stepper coil b hi
• Stepper coil b lo
• System ground
• Tan
• Tcc clutch ctrl
• Test, or start
• Throttle actuator sol ctrl
• Throttle body fuel injector #1 (top of throttle body unit)
• Throttle body fuel injector #2 (top of throttle body unit)
• Throttle position sensor in
• Trans input speed in hi
• Trans input speed in lo
• Transmission input shaft speed sensor (left side of trans- mission)
• Vss buffer signal

7.4L (VIN N), Engine Performance Wiring Diagrams, A/T (2 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 7.4L (VIN N), Engine Performance Wiring Diagrams, A/T (2 of 3) for GMC Cab & Chassis C2500 1994:

• (center rear
• Accy
• Bulb test
• Distributor
• Engine coolant temperature sensor (right top front of engine)
• Fuse block
• Gauges fuse 20a
• Hot at all times
• Hot in run, bulb test, or start
• Ignition coil (center rear of engine)
• Ignition switch
• Instrument cluster
• Knock sensor (right side of engine, below exhaust manifold)
• Lock
• Manifold absolute pressure sensor (right rear top of engine)
• Nca
• Of engine)
• Off
• Pnk
• Red
• Run
• Service engine soon indicator
• Start
• Tachometer test lead
• Tcc/brake switch (top of brake pedal bracket)
• Throttle position sensor (right side of throttle body)

7.4L (VIN N), Engine Performance Wiring Diagrams, A/T (3 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 7.4L (VIN N), Engine Performance Wiring Diagrams, A/T (3 of 3) for GMC Cab & Chassis C2500 1994:

• C12
• C13
• C14
• C15
• Cluster
• Data link connector (under left side of i/p)
• Fuel pump and sender
• Fuel pump in-line fuse 20a
• Fuel pump oil pressure switch (left rear of engine, near exhaust manifold)
• Fuel pump relay (right rear of engine compartment, near battery junction block)
• Fuse block
• G110 (left top front of engine)
• Heavy duty electronic 4-speed automatic overdrive transmission
• Hot at all times
• Hot in run or start
• Instrument
• Oil press in
• Oxygen sensor (left exhaust manifold)
• Pnk
• Pressure control solenoid
• Range mode selector
• Red
• Shift solenoid 1-2
• Shift solenoid 2-3
• Tach in
• Tan
• Throttle actuator solenoid (on throttle body unit)
• Torque converter clutch solenoid
• Trans fuse 10a
• Trans- mission temp sensor
• Vehicle speed sensor (left rear side of transmission)
• Vehicle speed sensor buffer (under right end of i/p)
• Vss in

7.4L (VIN N), Engine Performance Wiring Diagrams, M/T (1 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 7.4L (VIN N), Engine Performance Wiring Diagrams, M/T (1 of 3) for GMC Cab & Chassis C2500 1994:

• (4.3l only)
• (7.4l only)
• (left top front
• 12v battery
• 12v ignition
• 5v return a
• 5v return b
• 5v sensor ref
• A/c on signal in
• A10
• A11
• A12
• A13
• A14
• A15
• A16
• Air conditioning system
• B10
• B11
• B12
• B13
• B14
• B15
• B16
• Brake sw to pcm
• C215
• C218
• Coolant temp sensor
• Cruise control system
• Cruise ind reg grd
• Distributor ref hi
• Distributor ref lo
• Dlc
• Dlc serial data
• E10
• E11
• E12
• E13
• E14
• E15
• E16
• Ecm-ign fuse 10a
• Egr valve solenoid
• Egr valve solenoid (4.3l only) (left rear top of engine)
• Elec fuel pump in
• Engine control module (under right side of i/p)
• Evap canister purge ctrl
• Evaporative canister purge solenoid (on engine)
• F10
• F11
• F12
• F13
• F14
• F15
• F16
• Fuel pump relay ctrl
• Fuse block
• G110
• Hot in run
• Hot in run, bulb
• Idle air control unit (right rear of tbi unit)
• Ignition bypass
• Ignition control (ic)
• Inj fuse 10a
• Knock sensor in
• Linear egr position in
• Lo side inj a
• Lo side inj b
• Map sensor in
• Mil indicator ctrl
• Of engine)
• Or start
• Oxygen sensor hi
• Oxygen sensor lo
• Red
• Stepper coil a hi
• Stepper coil a lo
• Stepper coil b hi
• Stepper coil b lo
• System ground
• Tan
• Test, or start
• Throttle actuator ctrl
• Throttle body fuel injector #1 (top of throttle body unit)
• Throttle body fuel injector #2 (top of throttle body unit)
• Throttle position sensor in
• Upshift ind ctrl
• Vss buffer signal

7.4L (VIN N), Engine Performance Wiring Diagrams, M/T (2 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 7.4L (VIN N), Engine Performance Wiring Diagrams, M/T (2 of 3) for GMC Cab & Chassis C2500 1994:

• (4.3l only)
• (center rear
• Accy
• Bulb test
• Distributor
• Engine coolant temperature sensor (right top front of engine)
• Fuse block
• Gauges fuse 20a
• Hot at all times
• Hot in run, bulb test, or start
• Ignition coil (center rear of engine)
• Ignition switch
• Instrument cluster
• Knock sensor (4.3l only) (rear of engine)
• Knock sensor (right side of engine, below exhaust manifold)
• Linear egr regulator solenoid valve (7.4l only) (right top of engine)
• Lock
• Manifold absolute pressure sensor (right rear top of engine)
• Nca
• Of engine)
• Off
• Pnk
• Run
• Service engine soon indicator
• Start
• Tachometer test lead
• Tcc/brake switch (top of brake pedal bracket)
• Throttle position sensor (right side of throttle body)
• Up- shift indic- ator

7.4L (VIN N), Engine Performance Wiring Diagrams, M/T (3 of 3) for GMC Cab & Chassis C2500 1994

List of elements for 7.4L (VIN N), Engine Performance Wiring Diagrams, M/T (3 of 3) for GMC Cab & Chassis C2500 1994:

• (4.3l only)
• (4.3l)
• (7.4l)
• 4wd fuse 25a
• C12
• C13
• C14
• C15
• Cluster
• Data link connector (under left side of i/p)
• Fuel pump and sender
• Fuel pump in-line fuse 20a
• Fuel pump oil pressure switch (left rear of engine, near exhaust manifold)
• Fuel pump relay (right rear of engine compartment, near battery junction block)
• Fuse block
• G110 (left top front of engine)
• G117 (rear of right cylinder head)
• Heated oxygen sensor (4.3l) (in exhaust y-pipe)
• Hot at all times
• Hot in run
• Instrument
• Oil press in
• Oxygen sensor (7.4l) (left exhaust manifold)
• Red
• Tach in
• Tan
• Throttle actuator solenoid (7.4l only) (on throttle body unit)
• Vehicle speed sensor (left rear side of transmission)
• Vehicle speed sensor buffer (under right end of i/p)
• Vss in