Engine Control Module 2

Engine Control Module 2

Special tools, testers and auxiliary items required

• Heat Gun 220 V/50 Hz (VAS 1978/14) with Nozzle Attachment from Wiring Harness Repair Kit (VAS 1978)

• Small, Commercially Available Locking Pliers (vise grips)

• The Engine Control Module (ECM) - 1 - is bolted to a protective housing - 5 -. To make removing the shear bolts - 4 - for the retaining tabs - 2 - more difficult, the threads are coated with locking compound.





• To disconnect the connectors from the ECM (for example to connect the test box or to replace the ECM), the protective housing must be removed.

Removing

- If the engine control module is replaced, select the replace engine control module diagnostic item in the guided functions operating mode on the vehicle diagnosis and service system (VAS 5052).

- Turn the ignition and remove the ignition key.

- Remove the left engine compartment trim - 1 -. Refer to => [ Engine Compartment Trim ] Engine Compartment Trim.





- Disengage the gas-filled strut to remove the engine compartment trim.

- Open the four nuts on the engine control module 2 (J624) retaining clips and tilt the clips to the side.

- Remove the engine control module 2 - 3 -.





The engine control module is secured with a retainer and shear bolts are a protective housing to make it more difficult to access the connectors.

The threads of the shear bolts - 4 - (that are not installed in ECM) are coated with locking compound. For this reason, the threads must be heated with the heat gun to remove both bolts.





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





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





CAUTION!
By heating the threads, the retaining tabs, shear bolts and parts of the metal housing become very hot. Do not burn yourself on this! Make sure that only the threads are heated as much as possible, and not any of the surrounding parts. Possibly cover these parts.

Warm threads on connector side of shear bolts as shown in illustration.

Switch on heat gun and heat the bolt for approximately 20 to 30 seconds.





- Remove shear bolts with locking pliers (see direction of - arrow -).





- Both shear bolts that are screwed into the ECM do not require heating to be removed. They can be removed without heat.

- Disconnect metal retainers from connectors.

- Remove both retainer bolts from engine control module 2.

- Disengage connector from engine control module 2 and remove connector.

- Remove the old engine control module 2 and connect the new one.

Installing

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

- After that, the engine control module 2 must be equipped with the metal retainer.

- Clean threaded holes for shear bolts of locking compound residue. Cleaning can be performed with a thread cutter (tap).

- Always use new shear bolts.

Perform the following step after installing a new engine control module:

- Activate the engine control module in the guided functions operating mode under replace engine control module on the vehicle diagnosis and service system (VAS 5052).