Leak Detection Pump Checking

Leak Detection Pump Checking

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram.

Test requirements

• The Leak Detection Pump (LDP) (V144) fuse 15 in fuse panel B is OK.

• The ignition switched Off.

Test procedure

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

Start diagnosis

- Remove the right rear wheel housing liner. Refer to the Repair Information.

- Disconnect the Leak Detection Pump (LDP) (V144) electrical harness connector - 2 -.





Checking internal resistance

- Using a multimeter, check the Leak Detection Pump (LDP) (V144) for resistance as follows:










If the specified values were Not obtained:

- Replace the Leak Detection Pump (LDP) (-V144-). Refer to the Repair Information.

If the specified values are obtained:

Checking voltage supply

• The voltage for the Leak Detection Pump (LDP) (-V144-) is supplied via fuse 15 in fuse panel B.

- Check the Leak Detection Pump (LDP) (-V144-) for voltage.

- Using a multimeter, check the Leak Detection Pump (LDP) (-V144-)electrical harness connector terminal 3 for voltage. Connect the negative multimeter lead to engine ground.





- Turn the ignition switch On.

Specified value: Battery voltage.

- Switch the ignition Off.

If the specified value was Not obtained:

- Remove fuse 15 in Fuse Panel B. Using a multimeter, check the Leak Detection Pump (LDP) (-V144-) wiring from terminal 3 to fuse 15 in Fuse Panel B.

Specified value: Wire resistance max 1.5 ohms.

If the specified value was Not obtained:

- Check the wiring for high resistance or an open circuit.

- Check the electrical harness connector for damage, corrosion, loose or broken terminals.

- If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring or if the voltage supply was OK:

Checking wiring

- Remove the Motronic Engine Control Module (ECM) (J623). Refer to the Repair Information.

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






Specified value: 1.5 ohms max.

If the specified value was Not obtained:

- Check the wiring for high resistance or an open circuit.

- Check the electrical harness connector for damage, corrosion, loose or broken terminals.

- If necessary, repair the faulty wiring connection.

If no malfunction is found in wiring and the voltage and resistance was OK:

- Replace the Motronic Engine Control Module (ECM) (J623). Refer to the Repair Information.

Assembly is performed in the reverse order of the removal, note the following:

- Install the right rear wheel housing liner. Refer to the Repair Information.

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 Modes 01 - 09.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.