Engine Control Module: Service and Repair
Engine Control Module
• Modified anti-theft protection has been implemented since 11.06. Identifying feature: locking bracket instead of a locking plate.
- For removal and installation of the Engine Control Module (ECM), refer to one of the following:
=> [ Without Anti-Theft Immobilizer ]
=> [ With Anti-Theft Immobilizer and Locking Plate ]
=> [ With Anti-Theft Immobilizer and Locking Bracket ]
Without Anti-Theft Immobilizer
• If the Engine Control Module (ECM) will be replaced, connect the vehicle diagnostic tester and perform the "Replacing Engine Control Module" guided function.
DANGER!
On vehicles with heavy duty suspension, vehicle must be limited to a maximum speed of 210 km/h with the ECM. At speeds above 210 km/h, damage to the input shafts can occur. Perform the Guided Function "Limit maximum speed" with the vehicle diagnostic tester.
Removing
- Turn the ignition off.
- Remove windshield wiper arms.
- Remove the plenum chamber cover.
- Disconnect the connector - 1 - from the heated windshield control module (J505).
- Slide the connector latches - 2 - on the ECM outward and remove both connectors.
- Remove the ECM bracket bolts - 3 -.
- Remove ECM bracket with ECM from the plenum chamber.
- Press the release latches - 1 - outward and slide the ECM - 2 - from the bracket.
Installing
- Slide the ECM - 1 - into the bracket in the - direction of the arrow -.
- Place the bracket with ECM onto the bracket - 4 - in the plenum chamber.
Tightening specifications for the plenum chamber bracket nuts: 6 Nm.
- Tighten the ECM bracket bolts - 3 - to 7 Nm.
- Connect the connector to the ECM and slide the latches - 2 - inward.
- Connect the connector - 1 - to the heated windshield control module.
- Install the plenum chamber cover.
- Install the windshield wiper arms.
With Anti-Theft Immobilizer and Locking Plate
• If the Engine Control Module (ECM) will be replaced, connect the vehicle diagnostic tester and perform the "Replacing Engine Control Module" guided function.
DANGER!
On vehicles with heavy duty suspension, vehicle must be limited to a maximum speed of 210 km/h with the ECM. At speeds above 210 km/h, damage to the input shafts can occur. Perform the Guided Function " Limit maximum speed" with the vehicle diagnostic tester.
Special tools, testers and auxiliary items required
• Hot Air Gun from Wiring Harness Repair Kit (VAS 1978 B)
• Small Nozzle Attachment from Wiring Harness Repair Kit (VAS 1978 B)
• Locking Pliers
Removing
- Turn off the ignition.
- Remove the windshield wiper arms.
- Remove the plenum chamber cover.
• The threads of the shear bolts are equipped with locking compound. By heating the shear bolts using a hot air gun, the inhibition effect of the locking compound is lowered.
CAUTION!
Cover the wires, connectors and control modules near the ECM to prevent them from being burned.
Perform the adjustments on the hot air gun - 4 - as shown:
- Turn the potentiometer for the temperature adjustment - 2 - to maximum heat output (600 °C (1112 °F).
- Move the two stage switch for air quantity - 3 - to position 3.
CAUTION!
By heating the shear bolts, parts of the protective housing are heated intensely. Wear protective gloves to prevent injuries.
- Guide the heat gun nozzle onto the shear bolts.
- Turn the heat gun on and heat the shear bolts.
- Remove the shear bolts - 2 - using pliers on the bolt head.
The procedure for the second shear bolt is the same.
- Disconnect the connector - 1 - from the heated windshield control module (J505).
- Lift the cover - 1 - and pull it forward.
- Slide the connector latches - 1 - on the ECM outward and remove both connectors.
- Remove the bracket with ECM from the plenum chamber.
- Press the release latches - 1 - outward and slide the ECM - 2 - from the bracket.
Installing
- Slide the ECM - 1 - into the bracket in the - direction of the arrow -.
- Place the bracket with ECM onto the bracket in the plenum chamber.
Tightening specification of the plenum chamber bracket nuts: 6 Nm.
- Connect the connector to the ECM and slide the latches - 1 - inward.
- Slide the cover - 1 - over the ECM and press it downward.
- Tighten the new shear bolts - 2 - uniformly until the bolt heads shear off.
- Connect the connector - 1 - to the heated windshield control module.
- Install the plenum chamber cover.
- Install the windshield wiper arms.
With Anti-Theft Immobilizer and Locking Bracket
• If the Engine Control Module (ECM) will be replaced, connect the vehicle diagnostic tester and perform the "Replacing Engine Control Module" guided function.
DANGER!
On vehicles with heavy duty suspension, vehicle must be limited to a maximum speed of 210 km/h with the ECM. At speeds above 210 km/h, damage to the input shafts can occur. Perform the Guided Function " Limit maximum speed" with the vehicle diagnostic tester.
Special tools, testers and auxiliary items required
• Locking Pliers
Removing
- Turn off the ignition.
- Remove the windshield wiper arms.
- Remove the plenum chamber cover.
• In order to prevent the control module from coming in contact with water, some control modules have a cover. It is secured to the ECM with bolts - 1 -.
- Remove the cover bolts - 1 -.
- Remove the cover carefully, if present.
- Cover the plenum chamber with a clean cloth so that it does not get scratched.
- Raise the ECM with bracket slightly.
- Release the ECM - arrows - and pull it out slightly.
- Bend the raised ends - 1 - of the bracket outward.
- Remove the shear bolts - 2 - with locking pliers and remove the bracket.
- Slide the connector latches - 1 - on the ECM outward and remove both connectors.
- Remove the ECM.
Installing
- Slide the ECM - 1 - in the - direction of the arrow - into the bracket until it engages.
- Place the bracket with ECM onto the bracket in the plenum chamber.
Tightening specification of the plenum chamber bracket nuts: 6 Nm.
- Connect the connector on the ECM and slide the latches - 1 - inward.
- Take a new locking bracket and tighten the new shear bolts evenly until the bolt heads shear off.
- Install the plenum chamber cover.
- Install the windshield wiper arms.