12 51 001 Replacing Wiring Harness Section for Engine

12 51 001 Replacing Wiring Harness Section For Engine (N54, N54T)







IMPORTANT: Read and comply with notes on protection against electrostatic discharge (ESD protection).







Necessary preliminary tasks:
- Read out the fault memory of the DME control unit.
- Switch off ignition.
- Disconnect battery earth lead.
- Remove intake plenum.
- Remove charge air duct.







Unlock fasteners (1) from below and slide upwards approx. 10 mm.
Unlock locks (2) in direction of arrow.
Remove cover (3).







Unlock connector (1) and remove.
Release grommet (2) from electronics box.

Installation note:
Make sure grommet (2) is correctly seated in housing.
(watertightness).

Raise control unit (3) slightly.







Unlock connectors (1) using slide in direction of arrow and remove.







Short connector:
Unlock slide (2) in bore holes (1) and pull out of housing.
Unlock tab (3), pull contact carrier (4) in direction of arrow out of housing.







Long connector:
Press locking tab (1) in direction of arrow and pull contact carrier (2) out of housing.
Unlock and disconnect all plug connections of engine wiring harness section in electronics box.

Work step
Unlock plug connections on control sensors and disconnect
Unlock connector on heating pipe and disconnect
Unlock connector on alternator and disconnect
Unlock plug connection on knock sensors and disconnect
Release connector on crankshaft sensor and disconnect
Unlock connector on starter motor and disconnect
Unlock connector on high pressure pump and disconnect
Unlock connector on low pressure sensor and disconnect
Unlock connector on air conditioning compressor and disconnect
Remove rear underbody protection
Unlock plug connections on monitoring sensors and disconnect
Unlock connector on oil condition sensor and disconnect

Note







NOTE:
Check stored fault messages.
Delete fault memory.