12 42 510 Replacing battery positive lead (between starter motor and B+ support point) (S54)

Read fault memory. Switch off ignition.

Observe safety instructions for handling vehicle battery. Refer to 61 00... SAFETY INSTRUCTIONS FOR HANDLING VEHICLE BATTERY .

Remove front underbody protection.

Observe instructions for disconnecting and connecting battery. Refer to 12 00... Disconnecting and connecting battery .

Disconnect battery negative lead from battery and lay to one side.

Unclip battery positive lead from clips (1).

Fig 1: Unclipping Battery Positive Lead

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Feed battery positive lead out of cable duct.

Fold back protective cap (1).

Fig 2: Disconnecting Battery Positive Lead From Connection Point

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Release nut (2).

Installation :

Tightening torque, 12 51 4AZ. Refer to 12 51 ENGINE WIRING HARNESS .

Disconnect battery positive lead (3) from connection point.

Detach holder of battery positive lead on intake air manifold:

Fig 3: Detaching Holder On Intake Air Manifold

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Gently raise lug (1) and slide holder upwards.

Remove reinforcement plate on front axle support.

CAUTION: The section "Removing and installing reinforcement plate on front axle support" contains important installation instructions.

NOTE: For a better overview, this work step is shown without the intake air manifold and from above. Carry out the work from below.

Release nut.

Fig 4: Disconnecting Battery Positive Lead From Starter Motor

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Installation :

Tightening torque, 12 41 4AZ. Refer to 12 41 STARTER AND MOUNTING PARTS .

Disconnect battery positive lead from starter motor.

Remove battery positive lead.

NOTE: Interrogate fault memory of DME control unit.
Check stored fault messages.
Rectify faults.
Then clear fault memory.