Leak Detection Pump, Checking
Leak Detection Pump, Checking
Special tools, testers and auxiliary items required
- Multimeter.
- Wiring diagram.
Test requirements
- Fuse S345 OK.
- The Engine Component Power Supply Relay J757 OK.
- The ignition switched off.
NOTE: 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. General Diagnosis
- Remove the left rear wheel housing liner.
Start diagnosis
- 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:
Leak Detection Pump (LDP) Specified values
V144 electrical harness
connector terminals
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
- Using a Multimeter , check the Leak Detection Pump (LDP) -V144- electrical harness connector terminal 3 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:
- Check the Leak Detection Pump (LDP) -V144- electrical harness connector terminal 3 to the Engine Component Power Supply Relay J757 socket 2/87 for an open circuit, short circuit to each other, Battery (+), and Ground (GND).
- 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 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 40 for resistance.
- Using a Multimeter , check the Leak Detection Pump (LDP) -V144- electrical connector terminal 2 to Engine Control Module (ECM) J623 electrical connector T94 terminal 8 for resistance.
Leak Detection Pump (LDP) - Engine Control Module (ECM)
V144- electrical harness J623 electrical connector T94
connector terminals terminals or test box sockets
1 40
2 8
Specified value: 1.5 Ohms max.
If the specification is not obtained:
- Check the wiring for an open circuit, short circuit to each other, Battery (+), and Ground (GND).
- 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:
- Erase the 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. Monitors, Trips, Drive Cycles and Readiness Codes
- 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.
- Assembly is performed in the reverse of the removal.
Final procedures
After repair work, the following work steps must be performed in the mentioned 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