Motronic Engine Control Module, Replacing
Motronic Engine Control Module, Replacing
Engine Control Module (ECM) without Anti-Theft Immobilizer, Removing and Installing
• When the Motronic Engine Control Module (ECM) (J623) electrical harness connectors are disconnected, the adaptation values are erased and the DTC memory content remains intact.
Test procedure
- Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] Preliminary Check
Start diagnosis
Check the identification of the previous Motronic Engine Control Module (ECM) (J623) as follows:
- Connect the scan tool.
- Switch the ignition on.
- Using the scan tool, select "Vehicle information".
- Select " Calibration Identification" in vehicle information.
The electronic control module identification number will be displayed, e.g.: 06A906032NA 4983
- Record the electronic control module identification number.
- Switch the ignition off.
Procedure
- Switch off ignition.
- Remove wiper arms and plenum chamber cover.
- Remove plenum chamber bulkhead.
- Disengage forward harness connector- 1 - from Engine Control Module (ECM) and disconnect it.
- Pry up locking mechanism- 2 - slightly.
- Then slide Engine Control Module (ECM) out of retainer -arrow-.
- Now disengage rear harness connector from Engine Control Module (ECM) and disconnect it.
Installing
- Connect rear harness connector to Engine Control Module (ECM) and engage it.
- Slide Engine Control Module (ECM) on to retaining plate.
- Now connect front harness connector to Engine Control Module (ECM) and engage it.
- Install plenum chamber bulkhead.
- Install wiper arms and plenum chamber cover
Engine Control Module (ECM) with Anti-Theft Immobilizer, Removing and Installing
• When the Motronic Engine Control Module (ECM) (J623) electrical harness connectors are disconnected, the adaptation values are erased and the DTC memory content remains intact.
Special tools, testers and auxiliary items required
• Heat gun.
• Locking pliers
• Disc cutting tool
Test procedure
- Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] Preliminary Check
Start diagnosis
Check the identification of the previous Motronic Engine Control Module (ECM) (J623) as follows:
- Connect the scan tool.
- Switch the ignition on.
- Using the scan tool, select "Vehicle information".
- Select " Calibration Identification" in vehicle information.
The electronic control module identification number will be displayed, e.g.: 06A906032NA 4983
- Record the electronic control module identification number.
- Switch the ignition off.
Procedure
- Remove wiper arms and plenum chamber cover
- Remove plenum chamber bulkhead
• Thread of shear bolts is equipped with locking compound. By heating the shear bolts using a hot air gun, inhibition effect of the locking compound is lowered.
CAUTION!
Cover wires, harness connectors and control modules in the close vicinity of Engine Control Module (ECM) to prevent damage from burning. Observe operating instructions for the heat gun.
CAUTION!
The heat gun, shear bolts, and parts of the protective housing will become extremely hot. Use extreme caution when working with or handling these parts to avoid personal injury.
- Using a heat gun set at its medium setting, heat the shear bolt for approx. 20 to 25 seconds.
- Remove the shear bolt with locking pliers. Discard the used shear bolts.
Repeat the previous steps for the second shear bolt.
• If bolts cannot be removed, saw into heads of shear bolts so that two parallel surfaces are formed -arrows- and then remove them.
- Follow procedure as depicted below.
- Insert a screwdriver - A -- between protective housing and retaining plate - Arrow -..
- Pry protective housing upward using screwdriver - A - and pull it off sideways from retaining plate - Arrow -
- Disengage forward harness connector - 1 - from Engine Control Module (ECM) and disconnect it.
- Pry up locking mechanism - 2 - slightly
- Then slide Engine Control Module (ECM) out of retainer - Arrow -
- Now disengage rear harness connector from Engine Control Module (ECM) and disconnect it.
Installation
- Connect rear harness connector to Engine Control Module (ECM) and engage it.
- Slide Engine Control Module (ECM) on to retaining plate.
- Press catch - 2 - against engine control module.
- Now connect front connector - 1 - to Engine Control Module (ECM) and engage it.
- Slide protective housing on to retaining plate.
- Tighten shear bolts - 1 - uniformly until bolt heads shear off.
- Install plenum chamber bulkhead.
- Install wiper arms and plenum chamber cover.
Motronic Engine Control Module (ECM) (J623) reprogramming
- The new Engine Control Module (ECM) (J623) and immobilizer must be activated.
Final procedures
After the repair work, the following work steps must be performed in the following sequence:
1. Check the DTC memory. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Mode 03 - Read DTC Memory.
2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Mode 04 - Erase DTC Memory.
3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Readiness Code.