ENGINE PERFORMANCE – GMC Cab & Chassis C2500 1997 – SYSTEM WIRING DIAGRAMS

ENGINE PERFORMANCE

5.0L

5.0L (VIN M), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 5.0L (VIN M), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis C2500 1997:

• (attached to right rear of throttle body) idle air control (iac) valve
• (lower right front portion of engine block, near crankshaft) crankshaft position sensor
• (right side of engine) evaporative emission canister purge valve
• (right top of cyl. head) g120
• 1-2 shift sol. ctrl
• 2-3 shift sol. ctrl
• A/c comp rly ctrl
• A/c compressor clutch relay
• Bank 1 heated oxygen sensor no. 1 (in exhaust pipe in front of left catalytic converter)
• Bank 1 heated oxygen sensor no. 2 (in exhaust pipe in back of left catalytic converter)
• Bank 2 heated oxygen sensor no. 1 (in exhaust pipe in front of right catalytic converter)
• Cam posit sens sig
• Camshaft position sensor (in distributor)
• Coil
• Crank posit sens sig
• Ect sens sig
• Egr posit sig
• Egr sol ctrl
• Evap sol purge ctrl
• G120 (right front of engine block)
• Ground
• Iat sens sig
• Idle air ctrl (iac) a hi
• Idle air ctrl (iac) b lo
• Ign feed
• Ignition
• Inj no.1 ctrl
• Inj no.2 ctrl
• Inj no.3 ctrl
• Inj no.4 ctrl
• Inj no.5 ctrl
• Inj no.6 ctrl
• Inj no.7 ctrl
• Inj no.8 ctrl
• Knock sens sig
• Knock sensor (left side of engine block, below exhaust manifold, forward of starter)
• Left post ctylst hi
• Left post-ctylst lo
• Left sens hi (precat)
• Left sens lo (precat)
• Map sens input
• Mass air flow sens sig
• Nca
• Pnk
• Pnk c ignition feed
• Right post-ctlyst hi
• Right post-ctlyst lo
• Right sens hi (precat)
• Right sens lo (precat)
• S103
• S148
• S149
• S162
• Sens rtn
• Sens sig
• Sensor return
• Shift sol. ctrl
• Tan
• Tcc sol ctrl
• Tcc sol. ctrl
• Temp sens input
• Throttle posit sens
• Underhood fuse-relay center
• Vcm ground
• Vehicle control module (vcm) (in engine compartment, near brake pressure modulator valve (bpmv), at left front wheelhouse)
• Vehicle speed sensor (left rear side of transmission) (if equipped w/4wd) (left side of transfer case)
• Vss rtn
• Vss sig
• Vss signal

5.0L (VIN M), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 5.0L (VIN M), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis C2500 1997:

• (w/4l60-e trans.)
• (w/4l80-e trans.)
• 1-2 shift solenoid
• 2-3 shift solenoid
• 3-2 shift solenoid
• Automatic transmission
• Bank 2 heated oxygen sensor no. 2 (in exhaust pipe in back of right catalytic converter)
• Ecm-1 mini fuse 20a
• Eng-1 k7
• Exhaust gas recirculation (egr) valve (front of engine near thermostat housing)
• Fluid pressure (tfp) manual valve position switch
• Fluid temperature sensor (internal)
• Fuel inj. no.1
• Fuel inj. no.2
• Fuel inj. no.3
• Fuel inj. no.4
• Fuel inj. no.5
• Fuel inj. no.6
• Fuel inj. no.7
• Fuel inj. no.8
• Hot in run & start
• Ignition
• Mini fuse 20a l8
• Nca
• Note: fuel injectors are located in central sfi, center of intake manifold
• Pnk
• Pnk pnk pnk tan
• Pressure control solenoid valve
• Red
• S104
• S108
• S161
• Tan
• Tcc solenoid
• Torque convertor clutch pulse width modulation solenoid
• Under hood fuse-relay center
• W/4l60e 4-speed trans. only

5.0L (VIN M), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 5.0L (VIN M), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis C2500 1997:

• (engine harness, approx 13 cm from breakout to egr valve)
• (engine harness, approx 4.5 cm from breakout to egr valve)
• (engine harness, approx 7 cm in breakout to egr valve)
• (inside left frame rail, near rear crossmember) g415
• (not used)
• (right front of engine, near thermostat housing) g119
• (right top of cylinder head) g120
• (taillamp extension harness, approx 10 cm from fuel pump balance module breakout)
• Automatic transmission input shaft speed (a/t iss) sensor
• Balance fuel pump (on inside left frame rail near front of rear tank)
• Engine coolant temperature sensor (top right front of engine, near thermostat housing)
• Evaporative emission canister vacuum switch (right side of engine)
• Fuel pump & sender (in fuel tank)
• Fuel pump balance module (inside left side of frame rail near transmission crossmember)
• Fuel pump balance relay (on fuel pump balance module)
• Fuel pump/ oil pressure switch (top center rear of engine, behind distributor)
• Gauges fuse 4 10a
• Hot in off, run or start
• Hot in run or start
• Hot in run, or start
• I/p fuse block
• Ign e f7
• Ignition
• Input fuel gauge
• Input oil gauge
• Input tachometer
• Instrument cluster
• Intake air temperature sensor (in air intake duct)
• M/t only
• Map sensor (top right center of engine, near fuel injectors)
• Mass air flow sensor (air intake duct near air filter)
• Mini fuse 10a
• Output to gage
• Pnk
• Pnk a
• Pnk pnk tan
• Primary tank fuel level signal
• Relay ctrl
• S100
• S103
• S106
• S180
• S213
• S231
• S232
• S276
• S315
• S318
• Service engine soon indicator
• Speedometer input
• Tan
• Tan a
• Throttle position sensor (on side of throttle body)
• Trans fuse 20 10a
• Underhood fuse-relay center pnk
• Upshift lamp
• W/dual fuel tanks
• W/o dual fuel tanks
• W/o dual fuel tanks

5.0L (VIN M), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 5.0L (VIN M), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis C2500 1997:

• (engine compt., i/p harness, approx 6.5 cm into ebcm breakout)
• (engine harness, approx 13 cm into ebcm breakout)
• (engine harness, approx 38.5 cm from underhood fuse/relay center)
• (engine harness, approx 6.5 cm from underhood fuse-relay center breakout)
• (engine harness, approx 6.5 cm into ebcm breakout)
• (i/p harness, approx 20 cm from i/p cluster breakout)
• (or
• (right top of cylinder head) g120
• 20a
• 4wd input
• 5v ref. voltage
• A/c request signal
• A/t
• Air conditioning system
• Aux fan relay
• Brake sw input
• Brake switch assembly (top of brake pedal)
• Brake switch input
• Check eng lp ctrl
• Clutch pedal position switch (at top of clutch pedal)
• Cooling fans system
• Cruise control module (left rear side of engine compartment, on bulkhead)
• Cruise ctrl sig eng
• Cruise pdl sw out
• Data link connector (under left side of i/p)
• Distributor
• Ecm-b f11
• Electronic brake control module (ebcm) (near brake master cylinder, at left front wheelhouse)
• Est output sig
• Evap purge vac sw
• Force motor feed
• Force motor return
• Four whl dr sig
• Four whl dr sig lo
• Fuel a pump prime connector
• Fuel pump relay
• Fuel pump rly ctrl
• G120 (right top of cylinder head)
• Ground
• High voltage coil wire
• Hot at all times
• Hot in run
• I/p fuse block
• Ign coil out
• Ign input
• Ign timing sig.
• Ignition
• Ignition coil (right rear side of engine)
• Ignition coil driver (right rear side of engine)
• Ignition feed
• M/t
• M4 brake fuse 18 10a n3
• Mini fuse g12
• Pnk
• Pnk a
• Power steering control module (center of i/p)
• Pressure switch input
• Radio
• Red
• S101
• S103
• S111 (engine harness, approx 4 cm from breakout to taillamp harness)
• S150
• S151
• S152
• S153
• S163
• S221
• Sensor ground
• Sensor return
• Serial data sig
• Service circuit power
• Shift ind lp out
• Speed sensor
• Speed sensor input
• Stoplamp/ clutch switch input
• Switch signal
• Trans input speed rtn
• Trans input speed sig
• Transfer case control module (under i/p, on steering column support bracket)
• Transfer case switch (left top of transfer case)
• Transmissions system (four wheel drive indicator circuit
• Underhood fuse- relay center
• Vcm ground
• Vcm sig
• Vehicle control module (vcm) (in engine compartment, near brake pressure modulator valve (bpmv), at left front wheelhouse)
• Vss input
• Vss sig out

5.7L

5.7L (VIN R), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 5.7L (VIN R), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis C2500 1997:

• (attached to right rear of throttle body) idle air control (iac) valve
• (lower right front portion of engine block, near crankshaft) crankshaft position sensor
• (right side of engine) evaporative emission canister purge valve
• (right top of cyl. head) g120
• 1-2 shift sol. ctrl
• 2-3 shift sol. ctrl
• A/c comp rly ctrl
• A/c compressor clutch relay
• Bank 1 heated oxygen sensor no. 1 (in exhaust pipe in front of left catalytic converter)
• Bank 1 heated oxygen sensor no. 2 (in exhaust pipe in back of left catalytic converter)
• Bank 2 heated oxygen sensor no. 1 (in exhaust pipe in front of right catalytic converter)
• Cam posit sens sig
• Camshaft position sensor (in distributor)
• Coil
• Crank posit sens sig
• Ect sens sig
• Egr posit sig
• Egr sol ctrl
• Evap sol purge ctrl
• G120 (right front of engine block)
• Ground
• Iat sens sig
• Idle air ctrl (iac) a hi
• Idle air ctrl (iac) b lo
• Ign feed
• Ignition
• Inj no.1 ctrl
• Inj no.2 ctrl
• Inj no.3 ctrl
• Inj no.4 ctrl
• Inj no.5 ctrl
• Inj no.6 ctrl
• Inj no.7 ctrl
• Inj no.8 ctrl
• Knock sens sig
• Knock sensor (left side of engine block, below exhaust manifold, forward of starter)
• Left post ctylst hi
• Left post-ctylst lo
• Left sens hi (precat)
• Left sens lo (precat)
• Map sens input
• Mass air flow sens sig
• Nca
• Pnk
• Pnk c ignition feed
• Right post-ctlyst hi
• Right post-ctlyst lo
• Right sens hi (precat)
• Right sens lo (precat)
• S103
• S148
• S149
• S162
• Sens rtn
• Sens sig
• Sensor return
• Shift sol. ctrl
• Tan
• Tcc sol ctrl
• Tcc sol. ctrl
• Temp sens input
• Throttle posit sens
• Underhood fuse-relay center
• Vcm ground
• Vehicle control module (vcm) (in engine compartment, near brake pressure modulator valve (bpmv), at left front wheelhouse)
• Vehicle speed sensor (left rear side of transmission) (if equipped w/4wd) (left side of transfer case)
• Vss rtn
• Vss sig
• Vss signal

5.7L (VIN R), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 5.7L (VIN R), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis C2500 1997:

• (w/4l60-e trans.)
• (w/4l80-e trans.)
• 1-2 shift solenoid
• 2-3 shift solenoid
• 3-2 shift solenoid
• Automatic transmission
• Bank 2 heated oxygen sensor no. 2 (in exhaust pipe in back of right catalytic converter)
• Ecm-1 mini fuse 20a
• Eng-1 k7
• Exhaust gas recirculation (egr) valve (front of engine near thermostat housing)
• Fluid pressure (tfp) manual valve position switch
• Fluid temperature sensor (internal)
• Fuel inj. no.1
• Fuel inj. no.2
• Fuel inj. no.3
• Fuel inj. no.4
• Fuel inj. no.5
• Fuel inj. no.6
• Fuel inj. no.7
• Fuel inj. no.8
• Hot in run & start
• Ignition
• Mini fuse 20a l8
• Nca
• Note: fuel injectors are located in central sfi, center of intake manifold
• Pnk
• Pnk pnk pnk tan
• Pressure control solenoid valve
• Red
• S104
• S108
• S161
• Tan
• Tcc solenoid
• Torque convertor clutch pulse width modulation solenoid
• Under hood fuse-relay center
• W/4l60e 4-speed trans. only

5.7L (VIN R), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 5.7L (VIN R), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis C2500 1997:

• (engine harness, approx 13 cm from breakout to egr valve)
• (engine harness, approx 4.5 cm from breakout to egr valve)
• (engine harness, approx 7 cm in breakout to egr valve)
• (inside left frame rail, near rear crossmember) g415
• (not used)
• (right front of engine, near thermostat housing) g119
• (right top of cylinder head) g120
• (taillamp extension harness, approx 10 cm from fuel pump balance module breakout)
• Automatic transmission input shaft speed (a/t iss) sensor
• Balance fuel pump (on inside left frame rail near front of rear tank)
• Engine coolant temperature sensor (top right front of engine, near thermostat housing)
• Evaporative emission canister vacuum switch (right side of engine)
• Fuel pump & sender (in fuel tank)
• Fuel pump balance module (inside left side of frame rail near transmission crossmember)
• Fuel pump balance relay (on fuel pump balance module)
• Fuel pump/ oil pressure switch (top center rear of engine, behind distributor)
• Gauges fuse 4 10a
• Hot in off, run or start
• Hot in run or start
• Hot in run, or start
• I/p fuse block
• Ign e f7
• Ignition
• Input fuel gauge
• Input oil gauge
• Input tachometer
• Instrument cluster
• Intake air temperature sensor (in air intake duct)
• M/t only
• Map sensor (top right center of engine, near fuel injectors)
• Mass air flow sensor (air intake duct near air filter)
• Mini fuse 10a
• Output to gage
• Pnk
• Pnk a
• Pnk pnk tan
• Primary tank fuel level signal
• Relay ctrl
• S100
• S103
• S106
• S180
• S213
• S231
• S232
• S276
• S315
• S318
• Service engine soon indicator
• Speedometer input
• Tan
• Tan a
• Throttle position sensor (on side of throttle body)
• Trans fuse 20 10a
• Underhood fuse-relay center pnk
• Upshift lamp
• W/dual fuel tanks
• W/o dual fuel tanks
• W/o dual fuel tanks

5.7L (VIN R), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 5.7L (VIN R), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis C2500 1997:

• (engine compt., i/p harness, approx 6.5 cm into ebcm breakout)
• (engine harness, approx 13 cm into ebcm breakout)
• (engine harness, approx 38.5 cm from underhood fuse/relay center)
• (engine harness, approx 6.5 cm from underhood fuse-relay center breakout)
• (engine harness, approx 6.5 cm into ebcm breakout)
• (i/p harness, approx 20 cm from i/p cluster breakout)
• (or
• (right top of cylinder head) g120
• 20a
• 4wd input
• 5v ref. voltage
• A/c request signal
• A/t
• Air conditioning system
• Aux fan relay
• Brake sw input
• Brake switch assembly (top of brake pedal)
• Brake switch input
• Check eng lp ctrl
• Clutch pedal position switch (at top of clutch pedal)
• Cooling fans system
• Cruise control module (left rear side of engine compartment, on bulkhead)
• Cruise ctrl sig eng
• Cruise pdl sw out
• Data link connector (under left side of i/p)
• Distributor
• Ecm-b f11
• Electronic brake control module (ebcm) (near brake master cylinder, at left front wheelhouse)
• Est output sig
• Evap purge vac sw
• Force motor feed
• Force motor return
• Four whl dr sig
• Four whl dr sig lo
• Fuel a pump prime connector
• Fuel pump relay
• Fuel pump rly ctrl
• G120 (right top of cylinder head)
• Ground
• High voltage coil wire
• Hot at all times
• Hot in run
• I/p fuse block
• Ign coil out
• Ign input
• Ign timing sig.
• Ignition
• Ignition coil (right rear side of engine)
• Ignition coil driver (right rear side of engine)
• Ignition feed
• M/t
• M4 brake fuse 18 10a n3
• Mini fuse g12
• Pnk
• Pnk a
• Power steering control module (center of i/p)
• Pressure switch input
• Radio
• Red
• S101
• S103
• S111 (engine harness, approx 4 cm from breakout to taillamp harness)
• S150
• S151
• S152
• S153
• S163
• S221
• Sensor ground
• Sensor return
• Serial data sig
• Service circuit power
• Shift ind lp out
• Speed sensor
• Speed sensor input
• Stoplamp/ clutch switch input
• Switch signal
• Trans input speed rtn
• Trans input speed sig
• Transfer case control module (under i/p, on steering column support bracket)
• Transfer case switch (left top of transfer case)
• Transmissions system (four wheel drive indicator circuit
• Underhood fuse- relay center
• Vcm ground
• Vcm sig
• Vehicle control module (vcm) (in engine compartment, near brake pressure modulator valve (bpmv), at left front wheelhouse)
• Vss input
• Vss sig out

6.5L

6.5L (VIN F), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 6.5L (VIN F), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis C2500 1997:

• (engine harness, approx 43 cm from breakout to ebcm)
• (engine harness, approx 8 cm from fuel heater breakout)
• (engine jumper harness)
• (engine sensor harness)
• (front engine cover) crankshaft position (ckp) sensor)
• (front of engine)
• (i/p harness, approx 16 cm into i/p cluster breakout)
• (left lower front of engine) engine coolant temperature (ect) sensor
• (right top of cylinder head) g119
• 12v
• 3/2 shift sol.
• 4wd signal
• 5 volt ref
• 5 vref
• 5v ref volt
• A/c request sig
• A/c system
• A/t fluid pressure (tfp) manual valve position switch
• A10
• A11 3 mode cruise a12
• Anti-lock brakes system
• App 1 sig
• App 2 sig
• App 3 sig
• Automatic transmission input shaft speed (a/t iss) sensor (left side of transmission near front)
• B10
• B11
• B12
• Baro sensor input
• Boost pressure sensor
• Brake sw in
• Brake switch input
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• Cam posit sens sig rtn
• Camshaft posit sens
• Closure gnd
• Cruise control
• Cruise ctrl sw engage
• Cruise eng sw retard
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Ect temp sens in
• Engine crank sens input
• Exhaust gas recirculation (egr) control/ barometric (baro) pressure sensor (right of steering column)
• Force mtr hi
• Force mtr low
• Fuel pump input
• Fuel pump rly ctrl
• Fuel sol closure (5v sig)
• Fuel temp sens (5v sig)
• Glow plug "wait" lp out
• Glow plug relay
• Ground
• Heavy duty electronic 4-spd automatic overdrive transmission
• Intake air temperature (iat) sensor
• Intake man air temp sens
• Map sens input
• Nca
• On/off
• Pnk
• Powertrain control module (pcm) (under right end of i/p, above blower motor)
• Pressure control solenoid valve
• Radio
• Range mode sel a
• Range mode sel b
• Range mode sel c
• Red
• Resume
• S140
• S170
• S199
• S211
• S215
• S230
• Sensor gnd
• Set
• Shift sol. a
• Shift sol. b
• Switch
• Tan
• Timing stepper mtr (high)
• Timing stepper mtr (low)
• Transmission speed input
• Transmission temp input
• Transmission temperature sensor
• Transmissions system
• Vehicle speed input
• Vehicle speed sensor (on transmission, left rear side)
• Vehicle speed sensor buffer (below left side of i/p)
• Vss hi
• Vss output
• Vss rtn
• Vss sig

6.5L (VIN F), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 6.5L (VIN F), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis C2500 1997:

• (engine harness, approx 4 cm from i/p harness breakout)
• (engine jumper harness, toward fuel temperature sensor)
• 5 volt ref
• Accelerator pedal position (app) module (below i/p, attached to accelerator bracket)
• Brake switch assembly (at rear of brake pedal support bracket)
• Clutch pedal position (cpp) switch (m/t only) (top of clutch pedal)
• Cmp sig
• D2 trans fuse 20 20a e1
• D8 stop/haz fuse 1 20a c7
• Ecm h7
• Electronic brake control module (left frame rail, near center of vehicle)
• Engine shutoff solenoid
• Fuel f5
• Fuel solenoid
• Fuel solenoid driver
• Fuel temperature sensor
• Fuse 20a
• High res sig
• Hot at all times
• Hot in run
• Hot in run or start
• I/p fuse block
• M4 brake fuse 18 10a n3
• Pnk
• Pnk pnk
• Power distribution system
• Red
• S190
• S198
• S220 (i/p harness, approx 6 cm from steering column breakout)
• S222 (m/t) s152 (a/t)
• S299
• Sens grd
• Sol fuse 20a
• Tan d
• Timing stepper motor (top front of engine)
• Underhood fuse-relay center

6.5L (VIN F), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 6.5L (VIN F), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis C2500 1997:

• (engine harness, approx 37 cm from breakout to fuel relay center) s100
• (left frame rail, below driver's door)
• (right top of cylinder head)
• (right top of cylinder head) g119
• (taillamp extension harness, approx 10 cm from fuel pump balance module breakout)
• Ecm-b fuse 20a
• F11
• Fuel lift pump
• Fuel pump prime connector
• Fuel pump relay (in underhood fuse-relay center)
• Fuel pump/ oil pressure switch and sender (left rear of engine)
• G119
• G12
• Gauges fuse 4 10a
• Hot at all times
• Hot in run or start
• I/p fuse block
• Instrument cluster
• Instrument cluster system
• Instrument cluster system (fuel pump balance relay)
• Pnk
• Red
• S101
• S103
• S147
• S213
• S318
• Service engine soon indicator
• Service throttle soon indicator
• Tan
• Underhood fuse-relay center
• Vehicle speed input
• W/dual tanks
• W/o dual tanks
• Wait to start "glow plugs" indicator
• Water in fuel indicator
• Water in-fuel sensor

6.5L (VIN F), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 6.5L (VIN F), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis C2500 1997:

• "serv eng soon" ind
• "serv throttle soon" ind
• (engine harness, approx 13 cm into ebcm breakout)
• (engine harness, approx 13 cm into generator breakout)
• (engine harness, approx 34 cm from bulkhead to inside of pass compt)
• (engine harness, approx 64 cm from glow plug controller)
• (engine jumper harness, from fuel solenoid driver)
• (left side of i/p)
• (right top of cylinder head) g119
• 12v battery (fused)
• 12v battery fused
• 3/2 ctrl out
• A/c enable
• A/c system
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Data link connector (dlc)
• Egr sol output
• Egr valve sol putput
• Electronic brake brake control module (ebcm) (at left front wheelhouse)
• Eng-i k7
• Engine shutoff sol out
• Exhaust gas recirculation (egr) vent solenoid
• Exhaust gas recirculation egr solenoid (left rear top of engine)
• Fuel heater (top rear of engine)
• Fuel sol module (5 vref)
• Fuel sol module feed
• Fuse 10a
• Fuse 20a
• Fusible link
• Fusible links
• G119 (right top of cylinder head)
• Glow plug 1
• Glow plug 2
• Glow plug 3
• Glow plug 4
• Glow plug 5
• Glow plug 6
• Glow plug 7
• Glow plug 8
• Glow plug output
• Glow plug relay (left rear of engine near bulkhead)
• Glow plugs g4
• Grd
• Ground
• Hot at all times
• Hot in run or start
• Ign
• Ignition
• Maf
• Mass air flow (maf) sensor
• Pcm gnd
• Pnk
• Powertrain control module (pcm) (under right end of i/p, above blower motor)
• Red
• Relay ctrl
• S103
• S108
• S137
• S138
• S147
• S150
• S191
• S269
• Serial data sig
• Shift sol a input
• Shift sol b input
• Signal
• Tan
• Tps no.2 ref voltage
• Underhood fuse-relay center
• Wait to start ind
• Wastegate sol
• Wastegate solenoid

6.5L (VIN S), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 6.5L (VIN S), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis C2500 1997:

• (engine harness, approx 43 cm from breakout to ebcm)
• (engine harness, approx 8 cm from fuel heater breakout)
• (engine jumper harness)
• (engine sensor harness)
• (front engine cover) crankshaft position (ckp) sensor)
• (front of engine)
• (i/p harness, approx 16 cm into i/p cluster breakout)
• (left lower front of engine) engine coolant temperature (ect) sensor
• (right top of cylinder head) g119
• 12v
• 3/2 shift sol.
• 4wd signal
• 5 volt ref
• 5 vref
• 5v ref volt
• A/c request sig
• A/c system
• A/t fluid pressure (tfp) manual valve position switch
• A10
• A11 3 mode cruise a12
• Anti-lock brakes system
• App 1 sig
• App 2 sig
• App 3 sig
• Automatic transmission input shaft speed (a/t iss) sensor (left side of transmission near front)
• B10
• B11
• B12
• Baro sensor input
• Boost pressure sensor
• Brake sw in
• Brake switch input
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• Cam posit sens sig rtn
• Camshaft posit sens
• Closure gnd
• Cruise control
• Cruise ctrl sw engage
• Cruise eng sw retard
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Ect temp sens in
• Engine crank sens input
• Exhaust gas recirculation (egr) control/ barometric (baro) pressure sensor (right of steering column)
• Force mtr hi
• Force mtr low
• Fuel pump input
• Fuel pump rly ctrl
• Fuel sol closure (5v sig)
• Fuel temp sens (5v sig)
• Glow plug "wait" lp out
• Glow plug relay
• Ground
• Heavy duty electronic 4-spd automatic overdrive transmission
• Intake air temperature (iat) sensor
• Intake man air temp sens
• Map sens input
• Nca
• On/off
• Pnk
• Powertrain control module (pcm) (under right end of i/p, above blower motor)
• Pressure control solenoid valve
• Radio
• Range mode sel a
• Range mode sel b
• Range mode sel c
• Red
• Resume
• S140
• S170
• S199
• S211
• S215
• S230
• Sensor gnd
• Set
• Shift sol. a
• Shift sol. b
• Switch
• Tan
• Timing stepper mtr (high)
• Timing stepper mtr (low)
• Transmission speed input
• Transmission temp input
• Transmission temperature sensor
• Transmissions system
• Vehicle speed input
• Vehicle speed sensor (on transmission, left rear side)
• Vehicle speed sensor buffer (below left side of i/p)
• Vss hi
• Vss output
• Vss rtn
• Vss sig

6.5L (VIN S), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 6.5L (VIN S), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis C2500 1997:

• (engine harness, approx 4 cm from i/p harness breakout)
• (engine jumper harness, toward fuel temperature sensor)
• 5 volt ref
• Accelerator pedal position (app) module (below i/p, attached to accelerator bracket)
• Brake switch assembly (at rear of brake pedal support bracket)
• Clutch pedal position (cpp) switch (m/t only) (top of clutch pedal)
• Cmp sig
• D2 trans fuse 20 20a e1
• D8 stop/haz fuse 1 20a c7
• Ecm h7
• Electronic brake control module (left frame rail, near center of vehicle)
• Engine shutoff solenoid
• Fuel f5
• Fuel solenoid
• Fuel solenoid driver
• Fuel temperature sensor
• Fuse 20a
• High res sig
• Hot at all times
• Hot in run
• Hot in run or start
• I/p fuse block
• M4 brake fuse 18 10a n3
• Pnk
• Pnk pnk
• Power distribution system
• Red
• S190
• S198
• S220 (i/p harness, approx 6 cm from steering column breakout)
• S222 (m/t) s152 (a/t)
• S299
• Sens grd
• Sol fuse 20a
• Tan d
• Timing stepper motor (top front of engine)
• Underhood fuse-relay center

6.5L (VIN S), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 6.5L (VIN S), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis C2500 1997:

• (engine harness, approx 37 cm from breakout to fuel relay center) s100
• (left frame rail, below driver's door)
• (right top of cylinder head)
• (right top of cylinder head) g119
• (taillamp extension harness, approx 10 cm from fuel pump balance module breakout)
• Ecm-b fuse 20a
• F11
• Fuel lift pump
• Fuel pump prime connector
• Fuel pump relay (in underhood fuse-relay center)
• Fuel pump/ oil pressure switch and sender (left rear of engine)
• G119
• G12
• Gauges fuse 4 10a
• Hot at all times
• Hot in run or start
• I/p fuse block
• Instrument cluster
• Instrument cluster system
• Instrument cluster system (fuel pump balance relay)
• Pnk
• Red
• S101
• S103
• S147
• S213
• S318
• Service engine soon indicator
• Service throttle soon indicator
• Tan
• Underhood fuse-relay center
• Vehicle speed input
• W/dual tanks
• W/o dual tanks
• Wait to start "glow plugs" indicator
• Water in fuel indicator
• Water in-fuel sensor

6.5L (VIN S), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 6.5L (VIN S), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis C2500 1997:

• "serv eng soon" ind
• "serv throttle soon" ind
• (engine harness, approx 13 cm into ebcm breakout)
• (engine harness, approx 13 cm into generator breakout)
• (engine harness, approx 34 cm from bulkhead to inside of pass compt)
• (engine harness, approx 64 cm from glow plug controller)
• (engine jumper harness, from fuel solenoid driver)
• (left side of i/p)
• (right top of cylinder head) g119
• 12v battery (fused)
• 12v battery fused
• 3/2 ctrl out
• A/c enable
• A/c system
• C10
• C11
• C12
• C13
• C14
• C15
• C16
• D10
• D11
• D12
• D13
• D14
• D15
• D16
• Data link connector (dlc)
• Egr sol output
• Egr valve sol putput
• Electronic brake brake control module (ebcm) (at left front wheelhouse)
• Eng-i k7
• Engine shutoff sol out
• Exhaust gas recirculation (egr) vent solenoid
• Exhaust gas recirculation egr solenoid (left rear top of engine)
• Fuel heater (top rear of engine)
• Fuel sol module (5 vref)
• Fuel sol module feed
• Fuse 10a
• Fuse 20a
• Fusible link
• Fusible links
• G119 (right top of cylinder head)
• Glow plug 1
• Glow plug 2
• Glow plug 3
• Glow plug 4
• Glow plug 5
• Glow plug 6
• Glow plug 7
• Glow plug 8
• Glow plug output
• Glow plug relay (left rear of engine near bulkhead)
• Glow plugs g4
• Grd
• Ground
• Hot at all times
• Hot in run or start
• Ign
• Ignition
• Maf
• Mass air flow (maf) sensor
• Pcm gnd
• Pnk
• Powertrain control module (pcm) (under right end of i/p, above blower motor)
• Red
• Relay ctrl
• S103
• S108
• S137
• S138
• S147
• S150
• S191
• S269
• Serial data sig
• Shift sol a input
• Shift sol b input
• Signal
• Tan
• Tps no.2 ref voltage
• Underhood fuse-relay center
• Wait to start ind
• Wastegate sol
• Wastegate solenoid

7.4L

7.4L (VIN J), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 7.4L (VIN J), Engine Performance Wiring Diagrams (1 of 4) for GMC Cab & Chassis C2500 1997:

• (attached to right rear of throttle body) idle air control (iac) valve
• (engine harness, approx 11 cm into egr valve breakout)
• (lower right front portion of engine block, near crankshaft) crankshaft position sensor
• (right side of engine) evaporative emission canister purge valve
• (right top of cyl. head) g120
• 1-2 shift sol. ctrl
• 2-3 shift sol. ctrl
• A/c comp rly ctrl
• A/c compressor clutch relay
• Air pump relay ctrl
• Bank 1 heated oxygen sensor no. 1 (in exhaust pipe in front of left catalytic converter)
• Bank 1 heated oxygen sensor no. 2 (in exhaust pipe in back of right catalytic converter)
• Bank 2 heated oxygen sensor no. 1 (in exhaust pipe in front of right catalytic converter)
• Cam posit sens sig
• Camshaft position sensor (in distributor)
• Coil
• Crank posit sens sig
• Ect sens sig
• Egr posit sig
• Egr sol ctrl
• Evap sol purge ctrl
• G120 (right front of engine block)
• Ground
• Iat sens sig
• Idle air ctrl (iac) a hi
• Idle air ctrl (iac) b lo
• Ign feed
• Ignition
• Inj no.1 ctrl
• Inj no.2 ctrl
• Inj no.3 ctrl
• Inj no.4 ctrl
• Inj no.5 ctrl
• Inj no.6 ctrl
• Inj no.7 ctrl
• Inj no.8 ctrl
• Knock sens sig
• Knock sensor (left side of engine block, below exhaust manifold, forward of starter)
• Knock sensor (right side of engine block)
• Left post ctylst hi
• Left post-ctylst lo
• Left sens hi (precat)
• Left sens lo (precat)
• Map sens input
• Mass air flow sens sig
• Nca
• Pnk
• Pnk c ignition feed
• Pnk pnk pnk pnk pnk pnk pnk
• Right post-ctlyst hi
• Right post-ctlyst lo
• Right sens hi (precat)
• Right sens lo (precat)
• S103
• S145
• S148
• S149
• S162
• Sens rtn
• Sens sig
• Sensor return
• Tan
• Tcc sol ctrl
• Temp sens input
• Throttle posit sens
• Underhood fuse-relay center
• Vcm ground
• Vehicle control module (vcm) (in engine compartment, near brake pressure modulator valve (bpmv), at left front wheelhouse)
• Vehicle speed sensor (left rear side of transmission) (if equipped w/4wd) (left side of transfer case)
• Vss rtn
• Vss sig
• Vss signal

7.4L (VIN J), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 7.4L (VIN J), Engine Performance Wiring Diagrams (2 of 4) for GMC Cab & Chassis C2500 1997:

• 1-2 shift solenoid
• 2-3 shift solenoid
• Air injection reaction (a.i.r.) pump clutch (front of air injection pump, front of engine)
• Automatic transmission
• Bank 2 heated oxygen sensor no. 2 (in exhaust pipe in back of left catalytic converter)
• Ecm-1 mini fuse 20a
• Eng-1 k7
• Exhaust gas recirculation (egr) valve (front of engine near thermostat housing)
• Fluid pressure (tfp) manual valve position switch
• Fluid temperature sensor (internal)
• Fuel inj. no.1
• Fuel inj. no.2
• Fuel inj. no.3
• Fuel inj. no.4
• Fuel inj. no.5
• Fuel inj. no.6
• Fuel inj. no.7
• Fuel inj. no.8
• G119 (right front of engine block)
• Hot in run or start
• Ignition
• Mini fuse 20a l8
• Nca
• Note: fuel injectors are located in central sfi, center of intake manifold
• Pnk
• Pnk pnk pnk pnk pnk pnk
• Pnk pnk pnk tan pnk pnk
• Pressure control solenoid valve
• Red
• S104
• S108
• S147
• S154
• S155
• Secondary air injection reaction (a.i.r.) pump relay (underhood fuse/ relay center)
• Tan
• Torque convertor clutch pulse width modulation solenoid
• Under hood fuse-relay center

7.4L (VIN J), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 7.4L (VIN J), Engine Performance Wiring Diagrams (3 of 4) for GMC Cab & Chassis C2500 1997:

• (engine harness, approx 13 cm from breakout to egr valve)
• (engine harness, approx 4.5 cm from breakout to egr valve)
• (engine harness, approx 7 cm in breakout to egr valve)
• (inside left frame rail, near rear crossmember) g415
• (not used)
• (right front of engine, near thermostat housing) g119
• (right top of cylinder head) g120
• (taillamp extension harness, approx 10 cm from fuel pump balance module breakout)
• Automatic transmission input shaft speed (a/t iss) sensor
• Balance fuel pump (on inside left frame rail near front of rear tank)
• Engine coolant temperature sensor (top right front of engine, near thermostat housing)
• Evaporative emission canister vacuum switch (right side of engine)
• Fuel pump & sender (in fuel tank)
• Fuel pump balance module (inside left side of frame rail near transmission crossmember)
• Fuel pump balance relay (on fuel pump balance module)
• Fuel pump/ oil pressure switch (top center rear of engine, behind distributor)
• Gauges fuse 4 10a
• Hot in off, run or start
• Hot in run or start
• Hot in run, or start
• I/p fuse block
• Ign e f7
• Ignition
• Input fuel gauge
• Input oil gauge
• Input tachometer
• Instrument cluster
• Intake air temperature sensor (in air intake duct)
• M/t only
• Map sensor (top right center of engine, near fuel injectors)
• Mass air flow sensor (air intake duct near air filter)
• Mini fuse 10a
• Output to gage
• Pnk
• Pnk a
• Pnk pnk tan pnk pnk
• Primary tank fuel level signal
• Relay ctrl
• S100
• S103
• S106
• S146
• S180
• S213
• S231
• S232
• S276
• S315
• S318
• Service engine soon indicator
• Speedometer input
• Tan
• Tan a
• Throttle position sensor (on side of throttle body)
• Trans fuse 20 10a
• Underhood fuse-relay center pnk
• Upshift lamp
• W/california emissions
• W/dual fuel tanks
• W/o dual fuel tanks
• W/o dual fuel tanks

7.4L (VIN J), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis C2500 1997

List of elements for 7.4L (VIN J), Engine Performance Wiring Diagrams (4 of 4) for GMC Cab & Chassis C2500 1997:

• (engine compt., i/p harness, approx 6.5 cm into ebcm breakout)
• (engine harness, approx 13 cm into ebcm breakout)
• (engine harness, approx 38.5 cm from underhood fuse/relay center)
• (engine harness, approx 6.5 cm from underhood fuse-relay center breakout)
• (engine harness, approx 6.5 cm into ebcm breakout)
• (i/p harness, approx 20 cm from i/p cluster breakout)
• (or
• (right top of cylinder head) g120
• 20a
• 4wd input
• 5v ref. voltage
• A/c request signal
• A/t
• Air conditioning system
• Aux fan relay
• Brake sw input
• Brake switch assembly (top of brake pedal)
• Brake switch input
• Check eng lp ctrl
• Clutch pedal position switch (at top of clutch pedal)
• Cooling fans system
• Cruise control module (left rear side of engine compartment, on bulkhead)
• Cruise ctrl sig eng
• Cruise pdl sw out
• Data link connector (under left side of i/p)
• Distributor
• Ecm-b f11
• Electronic brake control module (ebcm) (near brake master cylinder, at left front wheelhouse)
• Est output sig
• Evap purge vac sw
• Force motor feed
• Force motor return
• Four whl dr sig
• Four whl dr sig lo
• Fuel a pump prime connector
• Fuel pump relay
• Fuel pump rly ctrl
• G120 (right top of cylinder head)
• Ground
• High voltage coil wire
• Hot at all times
• Hot in run
• I/p fuse block
• Ign coil out
• Ign input
• Ign timing sig.
• Ignition
• Ignition coil (right rear side of engine)
• Ignition coil driver (right rear side of engine)
• Ignition feed
• M/t
• M4 brake fuse 18 10a n3
• Mini fuse g12
• Pnk
• Pnk a
• Power steering control module (center of i/p)
• Pressure switch input
• Radio
• Red
• S101
• S103
• S111 (engine harness, approx 4 cm from breakout to taillamp harness)
• S150
• S151
• S152
• S153
• S163
• S221
• Sensor ground
• Sensor return
• Serial data sig
• Service circuit power
• Shift ind lp out
• Speed sensor
• Speed sensor input
• Stoplamp/ clutch switch input
• Switch signal
• Trans input speed rtn
• Trans input speed sig
• Transfer case control module (under i/p, on steering column support bracket)
• Transfer case switch (left top of transfer case)
• Transmissions system (four wheel drive indicator circuit
• Underhood fuse- relay center
• Vcm ground
• Vcm sig
• Vehicle control module (vcm) (in engine compartment, near brake pressure modulator valve (bpmv), at left front wheelhouse)
• Vss input
• Vss sig out