Leak Detection Pump, Checking

Leak Detection Pump, Checking

Observe all safety precautions: => [ Safety Precautions ] Safety Precautions

View clean working conditions: => [ Clean Working Conditions ] Clean Working Conditions

Use only gold-plated terminals when servicing any component with gold-plated electrical harness connector terminals.

For wiring diagrams, component locations, and connector views, Refer to the applicable wiring diagram.

Special tools, testers and auxiliary items required

• Multimeter

• Wiring diagram.

Test requirements

• The Leak Detection Pump (LDP) (V144) fuse 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 left rear wheel housing liner. Refer to appropriate service manual.

- 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 any of the specified values were not obtained:

- Replace the Leak Detection Pump (LDP) (V144). Refer to appropriate service manual.

- Go to Final procedures

If the specified values were obtained:

Checking voltage supply

• The voltage for the Leak Detection Pump (LDP) (V144) is supplied via the Fuse 7 (on fuse panel B) (SB 7).

- 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.











Switch the ignition ON.

Specified value: Battery voltage.

- Switch the ignition OFF.

If the specified value was not obtained:

- Check the wiring connection for an open circuit or short circuit to Engine ground

- Check the wiring connection for damage, corrosion, loose or broken terminals.

- If necessary, repair the faulty wiring connection and replace any open fuses

- Go to Final procedures

If the specified value was obtained:

Checking wiring

- Remove the Motronic Engine Control Module (ECM) (J623). Refer to appropriate service manual.

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











Specified value: 1.5 ohms max.

If the specified values were not obtained:

- Check the wiring connection for an open circuit, short circuit to Battery voltage or Ground

- Check the wiring connection for damage, corrosion, loose or broken terminals.

- If necessary, repair the faulty wiring connection.

- Go to Final procedures

If the specified value was obtained:

- Replace the Motronic Engine Control Module (ECM) (J623). Refer to appropriate service manual.

Final procedures

- Reassembly is performed in the reverse order of the removal.

- Install the left rear wheel housing liner. Refer to appropriate service manual.

- 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 - 0A.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 0A.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Programming and Relearning.