Manufacturer's Scan Tool

Engine Control Module, Replacing

Special tools, testers and auxiliary items required

• Wiring Harness Repair Kit (VAS 1978A).

• Wiring Harness Repair Kit (VAS 1978A)

• Commercially available locking pliers (vise grips)

• When connector is disconnected from the Engine Control Module (ECM), adaptation values are erased and content of DTC memory remains intact.

Removing

- Connect Vehicle Diagnostic, Testing and Information System (VAS 5051B) and select vehicle system "01 - Engine electronics". Thereby, the ignition must be switched on.

- On the screen of the vehicle diagnostic, testing, and information system (VAS 5051B), the control module identification and coding are displayed.





- Allow the control module identification to be displayed and then print it out.

- Switch off ignition.

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

- Remove plenum chamber cover - 1 - toward front.





- Pry off both covers - 3 - using a screwdriver.

- Loosen hex-nuts - 4 - by several turns.





- Loosen wiper arms - 2 - from the wiper axle by tilting slightly.

- Remove nuts completely and remove wiper arms.

- Remove securing clips - 1 - and remove cowl - 5 -.





- Remove cover for E-Box in plenum chamber, by removing the bolts - arrows -.





- Carefully pry off retainer bar with a screwdriver - arrow -.





- To increase difficulty with which the ECM connectors can be accessed, the ECM - 1 - is secured in a metal housing - 5 - with retaining tabs - 2 - and shear bolts - 3 and 4 -.





CAUTION!
To prevent damages (burning) of wire and harness connections, insulation and control modules, perform the following work procedures exactly! Observe operating instructions for heat gun.

- The threads of the shear bolts - 4 - (that are not screwed into the ECM) are coated with a 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 screwed into 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).





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





• Then, the shear bolts are heated with the heat gun. During this step, the holding effect that the locking compound has on the shear bolt threads is reduced, thereby allowing the shear bolts to be unscrewed easier.

• Cover all painted components to prevent damage that may be caused by the heat gun or the locking pliers.

CAUTION!
By heating the shear bolts, parts of the protective housing are heated intensely. Do not burn yourself on this! Make sure that only the shear bolts are heated as much as possible, and not any of the surrounding parts. Possibly cover these parts.

- Direct heat gun nozzle at shear bolt on the retaining tab.

- Switch on heat gun and heat bolt for approximately 20 to 25 seconds.





- Then grab bolt head with the locking pliers and unscrew the shear bolt.





The procedure for the second shear bolt is exactly the same.

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

Then, the engine control module (ECM) can be separated from the protective housing.

- Disengage connector retainers - arrows - and disconnect connectors - 1 and 2 - from Engine Control Module (ECM).





- Remove old ECM and install the new ECM.

Installing

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

- After that, he Engine Control Module (ECM) ( J623) 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.

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

- Activate (ECM) in "Guided Functions" operating mode under "Replace ECM".