Engine Control Module Power Supply Relay, Checking

Engine Control Module Power Supply Relay, Checking

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram.

• The Engine Control Module (ECM) Power Supply Relay (J363) supplies voltage to the ignition coils with power output stages and a few additional components. With the ignition switched on, 12 V must be present at the respective ignition coil connector, terminal 1.

Test requirement

• Fuses SA14, SA15 and SA18 OK.

• Battery voltage at least 12.5 V.

• The Ground (GND) connections at the engine and transmission OK.

• The generator OK.

• The ignition is switched off.

Test procedure

- Perform a preliminary check to verify the customer's complaint. Refer to => [ Preliminary Check ] Preliminary Check.





- Remove the rubber seal - 1 - from the plenum chamber cover.

- Remove the plenum chamber cover - 2 -.





- Using a screwdriver, remove the wiper arms caps - arrows -.

- Loosen the wiper arm nuts - arrows - several turns.

- Loosen wiper arms by gently rocking.

- Remove wiper arm nuts and wiper arms.





- Remove the screws - arrows - retaining the cowl grill - 1 -.

- Remove the cowl grill from the windshield.





- Remove the screws - arrows - and electronics box cover from the electronics box.





- Remove the Engine Control Module (ECM) Power Supply Relay (J363) - 3 - from the electronics box.

If the manufacturers test box is being used, perform the following step.

- Connect the Test Box 105 Pin (VAG1598/42) with Adapter Cable (1598/39-1).

If the manufacturers test box is not being used, perform the following step.

- Remove the Engine Control Module (ECM) (J623) => [ Engine Control Module, Replacing ] Engine Control Module, Replacing.

Checking voltage supply

- Switch the ignition on.

Using a Multimeter, check the electrical harness connector terminals to the Engine Control Module (ECM) (J623) electrical harness connector terminals for voltage.









Specified value: Battery voltage

If the specification is not obtained:

- Check the wiring for a short circuit to Battery positive (+) or an open circuit.

- If necessary, repair the wiring connection.

If no malfunctions are found in the wiring:

- Using a Multimeter or equivalent, check the following wiring connections for voltage according to wiring diagram:





Switch the ignition off.

Specified value: Battery voltage.

If the specified value is not obtained:

- Check the wiring connections for an open circuit according to the wiring diagram.

Specified value: Wire resistance max 1.5 ohms.

If no malfunctions are found in the wiring:

Checking wire connection





- Using a Multimeter, check the following wiring connections for resistance.





Specified value: Wire resistance max 1.5 ohms

If the specification is not obtained:

- Check the wiring for a short circuit to Battery positive (+) or an open circuit.

- If necessary, repair the wiring connection.

If no malfunctions are detected:

- Replace the Engine Control Module (ECM) Power Supply Relay (J363)

Assembly is performed in the reverse order of the removal.

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 ] Monitors, Trips, Drive Cycles and Readiness Codes.