12 63 520 Replacing main relay (M62, M54)

Switch off ignition.

Connect DIS Tester.

Detach sealing strips (1).

Fig 1: Detaching Sealing Strips

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Turn tommy bar through approx. 90°.

Remove cover.

Fig 2: Removing Cover

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Release lock (1).

Remove air funnel (2) towards top.

Fig 3: Removing Air Funnel

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Release screws.

Remove cover (1) on control unit box.

Fig 4: Removing Control Unit Box Cover

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Installation:

Insert fixtures (1) of cover for control unit box in openings (2).

Fig 5: Inserting Fixtures Of Cover For Control Unit Box In Openings

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Order:

Main relay of Digital Motor Electronics.
Engine fuses of Digital Motor Electronics.

Fig 6: Identifying Digital Motor Electronics Main Relay And Engine Fuses
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Notes On Troubleshooting:

If the starter motor cranks the engine during the starting sequence but the engine fails to fire, then:

Check engine fuses.
If fuses are blown, replace them completely with fuse holder.
Find out why fuses have blown.
Continue troubleshooting as per DIS instructions.