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 OK.
- The ignition switched off.

Procedure
- Remove the left rear wheel housing liner.







- 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:

Leak Detection Pump (LDP) Specified values
-V144- electrical harness
connector terminal
1 + 3 640 to 720 Ohms
2 + 3 15 to 17 Ohms

If any of the specifications are not obtained:
- Replace the Leak Detection Pump (LDP) -V144-.

If the specified values are obtained:

Checking voltage supply

NOTE: The voltage for the Leak Detection Pump (LDP) -V144- is supplied by the Engine Component Power Supply Relay J757.







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

Leak Detection Pump (LDP) Measure to
-V144- electrical harness
connector terminal
3 Engine Ground (GND)

- Operate the starter briefly.

Specified value: battery voltage.
- Switch the ignition off.

If the specified value was not obtained:







- Using a Multimeter , check the Leak Detection Pump (LDP) -V144- electrical harness connector terminal 3 to the Engine Component Power Supply Relay J757 terminal 2/87 for resistance.

Specified value: 1.5 Ohms

If the specified value was not obtained:
- Check the wiring for a short circuit to Ground (GND) 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 was OK:

Checking wiring
If the manufacturers test box is being used. Perform the following step.
- Install the test box.

If the manufacturers test box is not being used. Perform the following step.
- Remove the Engine Control Module (ECM) J623.
- Using a Multimeter , check the Leak Detection Pump (LDP) -V144- electrical connector terminal 1 to Engine Control Module (ECM) J623 electrical connector T94 terminal 20 for an open circuit.







- Using a Multimeter , check the Leak Detection Pump (LDP) -V144- electrical connector terminal 2 to Engine Control Module (ECM) J623 electrical connector T94 terminal 24 for an open circuit.

Leak Detection Pump (LDP) - Engine Control Module (ECM) J623
V144- electrical harness electrical connector T94 terminals or
connector terminals test box sockets
1 20
2 24

Specified value: 1.5 Ohms max.

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 found in wiring:
- Replace the Engine Control Module (ECM) J623.







- Install the rear engine cover - arrows -.

Final procedures
After the repair work, the following work steps must be performed in the following sequence:
1. Check the DTC memory. Diagnostic Mode 03 - Read DTC Memory
2. If necessary, erase the DTC memory. Diagnostic Mode 04 - Erase DTC Memory
3. If the DTC memory was erased, generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

- End of diagnosis.