Leak Detection Pump, Checking
Leak Detection Pump, Checking
Special tools, testers and auxiliary items required
• Multimeter.
• Wiring diagram.
Test requirements
• The Fuse (S282) fuse OK.
• The ignition switched off.
• The voltage for the Leak Detection Pump (LDP) (-V144-) is supplied by the Engine Component Power Supply Relay (J757).
Test procedure
- Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] Preliminary Check.
Start diagnosis
- Remove left rear wheel housing liner.
- Remove the Leak Detection Pump (LDP) (-V144-) nuts - arrows -.
- Remove the Leak Detection Pump (LDP) (-V144-) with bracket attached.
- 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 any of the specifications were not obtained:
- Replace the Leak Detection Pump (LDP) (-V144-).
If the specified values were obtained:
Checking voltage supply
- 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:
- Check the electrical harness connector for damage, corrosion, lose or broken terminals.
- Check the wiring connection from the Leak Detection Pump (LDP) (-V144-) electrical harness connector terminal 3 to theEngine Component Power Supply Relay (J757) terminal 2/87 for an open circuit or short to ground (GND).
- If necessary, repair the faulty wiring connection.
It the specification was obtained.
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 Motronic Engine Control Module (ECM) (J623). Refer to => [ Engine Control Module, Removing and Installing ] Service and Repair.
- Using a Multimeter, check the Leak Detection Pump (LDP) (-V144-) electrical harness connector terminals to theMotronic Engine Control Module (ECM) (J623) electrical harness connectors T94 terminals 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.
- If necessary, repair the wiring connection.
If no malfunction is found in wiring:
- Replace the Motronic Engine Control Module (ECM) (J623). Refer to => [ Engine Control Module, Removing and Installing ] Service and Repair.
Assembly is performed in the reverse order of removal.
- Install the left rear wheel housing liner.
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 ] Monitors, Trips, Drive Cycles and Readiness Codes.
- End of diagnosis.