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Leak Detection Pump V144, Checking






Leak Detection Pump V144, Checking

Special tools, testers and auxiliary items required

Multimeter.

Wiring diagram.

Test requirements

The Leak Detection Pump (LDP) (V144) fuse OK.

The ignition switched off.

The voltage for the Leak Detection Pump (LDP) (-V144-) is supplied via the Engine Control Module (ECM) Power Supply Relay (J271).

Test procedure

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

Start diagnosis

- Remove the left rear wheel housing liner.

- Disconnect the Leak Detection Pump (LDP) (V144) electrical harness connector - 3 -.





Checking internal resistance

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










If the specifications was not obtained:

- Replace the Leak Detection Pump (LDP) (-V144-).

If the specified values are obtained:

Checking voltage supply

The voltage for the Leak Detection Pump (LDP) (-V144-) is supplied via the Power Supply Relay (terminal 30, B+) (J317).

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

- Using a Multimeter, check the Leak Detection Pump (LDP) (-V144-) electrical harness connector terminal 3 to Ground (GND) for voltage.










- Operate the starter briefly.

Specified value: battery voltage.

- Switch the ignition off.

If the specified value was not obtained:

If the manufacturers test box is being used. Perform the following step.

- Install the Test Box 105 Pin (VAG1598/31).

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 J623, Replacing ] Engine Control Module J623, Replacing.

- Using a Multimeter, check the Leak Detection Pump (LDP) (V144)electrical harness connector terminal 3 to the Engine Control Module (ECM) Power Supply Relay (J271) terminal 2/87 for an open circuit according to wiring diagram.





Specified value: Wire resistance 1.5 ohms.

If the specification was not obtained:

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

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

- If necessary, repair the faulty wiring connection.

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

Checking output wiring

- Using a Multimeter, check the Leak Detection Pump (LDP) (V144) electrical connector terminals to Engine Control Module (ECM) (J623) electrical connector T121 for an open circuit.










Specified value: 1.5 ohms.

If the specification is not obtained:

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

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

- If necessary, repair the wiring connection.

If no malfunction is found in wiring:

- Erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Mode 04 - Erase DTC Memory

- Perform a road test to verify repair.

If the DTC does not return:

Repair complete, Generate readiness code. Refer to => [ Readiness Code Description ] Readiness Code Description.

- End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK:

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

- Assembly is performed in the reverse of the removal.

Final procedures

After 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 Description.

End of diagnosis