Engine Control Module Power Supply Relay, Checking
Special tools and workshop equipment 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 Requirements
- 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 .
-- 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 Cable1598/39-1. Refer to Component Locations Overview .
If the manufacturers test box is not being used, perform the following step.
-- Remove the Engine Control Module (ECM) -J623-. Refer to 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.
| Relay carrier (connector) position 3 Terminal | Engine Control Module (ECM)J623 Electrical Harness Connector Terminal or Test Box Socket |
|---|---|
| 4 | 69 |
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:
| Relay carrier (connector) position 3 Terminal | Measure to |
|---|---|
| 1 | Engine Ground (GND) |
| 2 | Engine Ground (GND) |
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 Ω.
If no malfunctions are found in the wiring:
Checking wire connection
-- Using a Multimeter --, check the following wiring connections for resistance.
| Relay Carrier (connector) Position 3 Terminal | Engine Control Module (ECM)J623Electrical Harness Connector Terminal or Test Box Socket |
|---|---|
| 2 | 3 |
Specified value: Wire resistance max 1.5 Ω
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-. Refer to Component Locations Overview .
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:
- Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
- If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
- If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .