Engine Control Module (ECM), removing and installing: Removing

If engine control module (ECM) was replaced, select diagnostic object "Replacing engine control module (ECM)" in "Guided Fault-Finding".
Turn ignition and remove ignition key.

Fig 1: Removing Rubber Seal For Plenum Chamber Cover & Plenum Chamber Cover

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Remove rubber seal - 1 - for plenum chamber cover.
Remove plenum chamber cover - 2 -.

Fig 2: Identifying Wiper Arm Nuts

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Pry off caps on wiper arms using a screwdriver.
Loosen nuts - arrows - by several turns.
Loosen wiper arms by gently rocking wiper arm. Remove nuts and remove wiper arms.

NOTE:

If wiper arm cannot be removed in this way, use a standard puller.

Fig 3: Removing Bolts For Cowl Grill

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Remove bolts - arrows - for cowl grill - 1 -.
Pull cowl grill off from windshield.

Fig 4: Removing Bolts And Cover For E-Box At Right In Engine Compartment

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Remove bolts - arrows - and remove cover for E-box at right in engine compartment.

CAUTION: The heater pump valve unit (left of E-box) becomes very hot during operation - Risk of burning!

Fig 5: Prying Off Retaining Clip With Screwdriver And Removing ECM From E-Box

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Carefully pry off retaining clip - 2 - with a screwdriver - arrows 1 and 2 - and remove ECM from E-box.

CAUTION: To avoid damage (burning) of wire connections and harness connectors, insulation and control modules, the following work steps must be adhered to exactly! Observe operating instructions for heat gun.

Fig 6: Performing Adjustments On Hot Air Gun

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Set adjustment on heat gun as shown in illustration, with temperature potentiometer - 2 - set to maximum heat and two-stage air flow switch - 3 - set to level "3".

NOTE:

Next, the threads of the protective housing in which the shear bolts are threaded is heated using the heat gun. This step decreases the locking effect of the locking compound on the shear bolt thread, thus allowing the shear bolts to be removed more easily.

CAUTION: By heating the shear bolts, parts of the protective housing will become extremely hot. Do not burn yourself on this! Ensure only the shear bolts are heated and not any of the surrounding parts. Possibly cover these parts.

Fig 7: Removing Protective Housing From Engine Control Module (ECM) J623

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Perform the following steps in order one after the other for both shear bolts - 4 -.

Fig 8: Using Heat Gun To Direct Heat Gun Nozzle At Shear Bolt Of Retaining Tab

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Direct heat gun nozzle at protective housing shear bolts.
Switch heat gun on and heat bolt for approx. 20 to 25 seconds.

Fig 9: Using Locking Pliers To Remove Shear Bolt

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Remove shear bolts with locking pliers - arrow -.

Fig 10: Removing Protective Housing From Engine Control Module (ECM) J623

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NOTE:

The threads of both shear bolts - 3 - that are installed in the ECM are not coated with a locking compound. The threads in the ECM housing must not be heated and do not require to be heated (unintentional heating of the ECM).

Remove both shear bolts - 3 -.
Separate retaining tab - 2 - of control module connector.
Release and pull off connectors from engine control module (ECM).

NOTE:

Adaptation values are erased when connectors are disconnected from the Engine Control Module (ECM), DTC memory content remains intact.