Engine Control Module (ECM), removing and installing

WARNING: This page is about a different car, the 2009 Audi A4, 2008 Audi A4, 2007 Audi A4, 2006 Audi A4, and 2005 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

Special tools, testers and auxiliary items required

Fig 1: Heat Gun, Adapter Nozzle And Pliers

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Heat Gun 220 V/50 Hz VAS 1978/14 - 1 - with nozzle attachment - 2 - from Wiring Harness Repair kit VAS 1978A
Locking pliers - 3 - (commercially available)

Fig 2: Removing Protective Housing From Engine Control Module (ECM) J623

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NOTE:

The Engine Control Module (ECM) - 1 - is bolted to a protective housing - 5 -. To make removal of shear bolts - 4 - for retaining tabs - 2 - more difficult, the threads are coated with locking compound.
To disconnect the connectors from the engine control module (ECM) (e.g. to connect the test box or to replace the ECM), the protective housing must be removed.

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 3: Identifying Plenum Chamber Cover & Removing Rubber Seal

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Remove rubber seal of plenum chamber cover in direction of - arrow -.
Remove plenum chamber cover - 1 - toward front.

Fig 4: Removing Securing Clips And Cowl

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Pry off both covers - 3 - using a screwdriver.
Loosen hex-nuts - 4 - by several turns.
Loosen wiper arms - 2 - from wiper axle by tilting slightly.
Remove nuts completely and remove wiper arms.

NOTE:

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

Disconnect securing clips - 1 - and remove cowl grille - 5 -.

Fig 5: Removing Screws And Cover From E-Box In Plenum Chamber

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Remove cover for E-Box in plenum chamber - arrows -.

Fig 6: Using Screwdriver To Remove Retainer Bar And Engine Control Module (ECM) J623

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Using a screwdriver, carefully pry off mounting bracket - arrows - and remove Engine Control Module (ECM) from E-Box.

NOTE:

Engine Control Module (ECM) remains connected at wiring harness.

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 7: 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 8: Removing Protective Housing From Engine Control Module (ECM) J623

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Perform the following steps in order on both shear bolts - 4 -.

Fig 9: 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 10: Using Locking Pliers To Remove Shear Bolt

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Remove shear bolts with locking pliers - arrow -.

Fig 11: Removing Protective Housing From Engine Control Module (ECM) J623

Courtesy of VOLKSWAGEN UNITED STATES, INC.

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 disconnect connectors from engine control module (ECM).

NOTE:

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

Installing

Installation is in reverse order of removal, note the following:

The ECM must be equipped with protective housing again.
Clean locking compound residue from shear bolt threaded holes. Cleaning can be performed with a thread cutter (tap).
Use new shear bolts.

After installing a new Engine Control Module (ECM), the following work steps must be performed:

Activate engine control module (ECM) in "Guided Fault-Finding" under "Replacing engine control module (ECM)".