12 51 001 Replacing wiring harness section for engine (M57T2)
IMPORTANT:
Read and comply with notes on ESD PROTECTION (ELECTRO STATIC DISCHARGE)
.
Necessary preliminary tasks:
- Read out fault memory of DME control unit
- Switch off ignition
- Disconnect battery negative lead. See 61 20 900 DISCONNECTING AND CONNECTING BATTERY NEGATIVE LEAD .
- Disconnect control unit, refer to REPLACING CONTROL UNIT
- Remove intake air manifold. See 11 61 050 REMOVING AND INSTALLING AIR INTAKE PLENUM (M57T2) .
- Remove underbody protection. See 51 47 490 REMOVING AND INSTALLING / REPLACING FRONT ASSEMBLY UNDERSIDE PROTECTION
Disconnect battery negative lead from battery and lay to one side
Unlock tab (1), pull contact carrier (2) in direction of arrow out of housing.
Release screws on cable duct (1).
ENGINE WIRING HARNESS REPLACEMENT PROCEDURE
| Work step | Note: |
|---|---|
| Unlock plug on lambda oxygen sensor and disconnect | |
| Unlock plug on diesel particulate filter temperature sensor and disconnect | |
| Unlock plug on exhaust system pressure sensor and disconnect | |
| Unlock plug on A/C compressor and disconnect | |
| Release nut and disconnect control line from starter motor | |
| Unlock plug on crankshaft sensor and disconnect | |
| Unlock plug on coolant temperature sensor and disconnect | |
| Unlock plugs of all glow plugs and disconnect | |
| Unlock plug on camshaft sensor and disconnect | |
| Unlock plug on air mass sensor and disconnect | |
| Unlock plug on injection system pressure control valve and disconnect | |
| Unlock plug on injection system pressure sensor and disconnect | |
| Unlock plug on fuel metering unit and disconnect | |
| Unlock plug on fuel temperature sensor and disconnect | |
| Unlock plug on oil pressure sensor and disconnect | |
| Unlock plug on electric switchover valve and disconnect | |
| Unlock plug on turbocharger and disconnect | |
| Unlock plug on oil condition sensor and disconnect | |
| Unlock plug on diesel particulate filter temperature sensor and disconnect | |
| Unlock plug on reversing light switch and disconnect | Manual transmissions only |
| Unlock plug on automatic transmission and disconnect | If necessary, remove exhaust system intermediate pipe |
| Unlock plug on preheating control unit and disconnect | |
| Unlock plug on alternator and disconnect | |
| Remove wiring harness Installation: Pay attention to installation position and attachment points |
NOTE:
Now clear the fault memory.