| A | Battery |
| B | Starter |
| C | Alternator |
| C1 | Voltage regulator |
| D | Ignition/starter switch |
| S162 | Fuse 1 (30) in fuse holder on battery |
| S163 | Fuse 2 (30) in fuse holder on battery |
| S176 | Fuse 4 (30) in fuse holder on battery |
| S177 | Fuse 5 (30) in fuse holder on battery |
| T2e | 2-pin connector, near starter (in models without air conditioning system) |
| T4 | 4-pin connector, near starter (in models with air conditioning system) |
| T6 | 6-pin connector, brown, in connector protective housing, on left in plenum chamber |
| 42 | Earth point, next to steering column |
| 49 | Earth point, on steering column |
| 135 | Earth connection 2, in dash panel wiring harness |
| 500 | Screw connection 1 (30), on relay plate |
| * | only models with glow plugs coolant heating |
| D | Ignition/starter switch |
| J4 | Dual tone horn relay |
| J59 | X-contact relief relay |
| J370 | Glow plug activation control unit, in centre plenum chamber |
| Q6 | Glow plugs, engine |
| S229 | Fuse 29 in fuse holder |
| S237 | Fuse 37 in fuse holder |
| T4u | 4-pin connector, in left engine compartment |
| T6 | 6-pin connector, brown, in connector protective housing, on left in plenum chamber |
| T14a | 14-pin connector, near battery |
| 501 | Screw connection 2 (30), on relay plate |
| 503 | Screw connection (75x), on relay plate |
| A2 | Positive connection (15), in dash panel wiring harness |
| A32 | Positive connection (30), in dash panel wiring harness |
| A80 | Connection 1 (X), in dash panel wiring harness |
| A98 | Positive connection 4 (30), in dash panel wiring harness |
| A104 | Positive connection 2 (15), in dash panel wiring harness |
| F8 | Kick-down switch |
| F60 | Idling speed switch |
| G79 | Accelerator position sender |
| J248 | Diesel direct injection system control unit, in centre plenum chamber |
| J317 | Terminal 30 voltage supply relay, above the central electrics |
| T6 | 6-pin connector, brown, in connector protective housing, on left in plenum chamber |
| T6a | 6-pin connector |
| T10h | 10-pin connector, blue, in connector protective housing, on left in plenum chamber |
| T14a | 14-pin connector, near battery |
| T121 | 121-pin connector |
| A98 | Positive connection 4 (30), in dash panel wiring harness |
| 502 | Screw connection 1 (30a), on relay plate |
| 504 | Screw connection 1 (87), on relay plate |
| A104 | Positive connection 2 (15), in dash panel wiring harness |
| G2 | Coolant temperature display sender |
| G62 | Coolant temperature sender |
| G71 | Intake manifold pressure sender |
| G72 | Intake manifold temperature sender |
| J248 | Diesel direct injection system control unit, in centre plenum chamber |
| N79 | Heater element for crankcase breather |
| T10 | 10-pin connector, orange, in connector protective housing, on left in plenum chamber |
| T10f | 10-pin connector, in front engine compartment |
| T10w | 10-pin connector, white, in connector protective housing, on left in plenum chamber |
| T14a | 14-pin connector, near battery |
| T121 | 121-pin connector |
| 131 | Earth connection 2, in engine compartment wiring harness |
| 608 | Earth point, in centre of plenum chamber |
| * | connection for radiator fan control unit/ radiator fan relay |
| ** | connection air conditioning system |
| --- | for models with heater element for crankcase breather only |
| J104 | ABS control unit with EDL |
| J248 | Diesel direct injection system control unit, in centre plenum chamber |
| J255 | Climatronic control unit |
| T10 | 10-pin connector, orange, in connector protective housing, on left in plenum chamber |
| T10w | 10-pin connector, white, in connector protective housing, on left in plenum chamber |
| T47a | 47-pin connector |
| T16b | 16-pin connector |
| T17a | 17-pin connector, behind centre dash panel |
| T121 | 121-pin connector |
| A121 | Connection (high bus), in dash panel wiring harness |
| A122 | Connection (low bus), in dash panel wiring harness |
| -●●- | only models with Climatronic |
| G40 | Hall sender |
| J248 | Diesel direct injection system control unit, in centre plenum chamber |
| N240 | Unit injector valve, No. 1 cyl. |
| N241 | Unit injector valve, No. 2 cyl. |
| N242 | Unit injector valve, No. 3 cyl. |
| N243 | Unit injector valve, No. 4 cyl. |
| T3a | 3-pin connector, on front of engine |
| T8u | 8-pin connector, on left of cylinder head |
| T121 | 121-pin connector |
| E48 | Connection (injectors), in injection system wiring harness |
| F27 | Connection (screening), in diesel direct injection wiring harness |
| # | from August 2004 |
| *** | up to July 2004 |
| G70 | Air mass meter |
| G81 | Fuel temperature sender |
| J248 | Diesel direct injection system control unit, in centre plenum chamber |
| N18 | Exhaust gas recirculation valve |
| N75 | Charge pressure control solenoid valve |
| N345 | Exhaust gas recirculation cooler change-over valve |
| T5 | 5-pin connector |
| T10f | 10-pin connector, in front engine compartment |
| T10w | 10-pin connector, white, in connector protective housing, on left in plenum chamber |
| T121 | 121-pin connector |
| E29 | Connection, in engine wiring harness |
| E45 | Cruise control system switch |
| E227 | Cruise control system (CCS) SET button |
| F36 | Clutch pedal switch |
| G28 | Engine speed sender |
| J248 | Diesel direct injection system control unit, in centre plenum chamber |
| T3 | 3-pin connector, on front of engine |
| T6 | 6-pin connector, brown, in connector protective housing, on left in plenum chamber |
| T10 | 10-pin connector, orange, in connector protective housing, on left in plenum chamber |
| T10e | 10-pin connector, black, in connector protective housing, on left in plenum chamber |
| T10s | 10-pin connector, next to steering column |
| T10w | 10-pin connector, white, in connector protective housing, on left in plenum chamber |
| T121 | 121-pin connector |
| 200 | Earth connection (screening) in engine compartment wiring harness*** |
| A27 | Connection (speed signal), in dash panel wiring harness |
| A155 | Connection 2 (86), in dash panel wiring harness |
| D74 | Connection (86), in engine compartment wiring harness |
| * | only models with manual gearbox |
| ** | only models with GND, models with multifunction display ⇒ Current Flow Diagram multifunction steering wheel for cruise control system and radio |
| # | from August 2004 |
| *** | up to July 2004 |
| F | Brake light switch |
| F47 | Brake pedal switch |
| J248 | Diesel direct injection system control unit, in centre plenum chamber |
| J359 | Low heat output relay*, in protective housing on left in engine compartment (53) |
| J360 | High heat output relay*, in protective housing on left in engine compartment (100) |
| Q7 | Glow plugs, coolant* |
| S13 | Fuse 13 in fuse holder |
| T6 | 6-pin connector, brown, in connector protective housing, on left in plenum chamber |
| T10e | 10-pin connector, black, in connector protective housing, on left in plenum chamber |
| T10w | 10-pin connector, white, in connector protective housing, on left in plenum chamber |
| T121 | 121-pin connector |
| A18 | Connection (54), in dash panel wiring harness |
| A155 | Connection 2 (86), in dash panel wiring harness |
| D50 | Positive connection (30), in engine compartment wiring harness |
| D98 | Connection (glow plugs), in engine compartment wiring harness |
| * | only models with glow plugs coolant heating |
| --- | for models with heater element for crankcase breather only |
| G | Fuel gauge sender** |
| G6 | Fuel system pressurisation pump |
| J17 | Fuel pump relay, on additional relay carrier above the relay plate |
| S228 | Fuse 28 in fuse holder |
| S232 | Fuse 32 in fuse holder |
| S234 | Fuse 34 in fuse holder |
| S243 | Fuse 43 in fuse holder |
| T6 | 6-pin connector, brown, in connector protective housing, on left in plenum chamber |
| T14a | 14-pin connector, near battery |
| 269 | Earth connection (sender earth) 1, in dash panel wiring harness |
| A71 | Connection (86), in dash panel wiring harness |
| A100 | Connection 2 (87), in dash panel wiring harness |
| B168 | Connection (86), in interior wiring harness |
| * | only models with multifunction display |
| ** | models with four-wheel drive ⇒ four-wheel drive Current Flow Diagram |
| *** | models with multifunction display and without Climatronic only |
| F1 | Oil pressure switch |
| G22 | Speedometer sender, on gearbox |
| G32 | Coolant shortage indicator sender |
| G266 | Oil level and oil temperature sender*** |
| S5 | Fuse 5 in fuse holder |
| S7 | Fuse 7 in fuse holder |
| T14a | 14-pin connector, near battery |
| 85 | Earth connection 1, in engine compartment wiring harness |
| 269 | Earth connection (sender earth) 1, in dash panel wiring harness |
| 608 | Earth point, in centre of plenum chamber |
| A20 | Connection (15a), in dash panel wiring harness |
| B163 | Positive connection 1 (15), in interior wiring harness |
| *** | only flexible service interval display |
| E86 | Multifunction display call-up button |
| E109 | Multifunction display memory switch |
| G17 | Ambient temperature sensor |
| G21 | Speedometer |
| H3 | Buzzer |
| J119 | Multifunction display |
| J255 | Climatronic control unit |
| J285 | Control unit in dash panel insert |
| J533 | Data bus diagnostic interface, in dash panel insert |
| K2 | Alternator warning lamp |
| K29 | Glow period warning lamp |
| K31 | Cruise control system warning lamp |
| T6e | 6-pin connector |
| T12a | 12-pin connector, behind centre dash panel |
| T16 | 16-pin connector, in centre dash panel, self-diagnosis connection |
| T20 | 20-pin connector |
| T32 | 32-pin connector, blue |
| T32a | 32-pin connector, green |
| A76 | Connection (diagnosis wire K), in dash panel wiring harness |
| * | only models with multifunction display |
| *** | models with multifunction display and without Climatronic only |
| -●- | only models with Climatronic |