Low Fuel Pressure Sensor G410, Checking

Low Fuel Pressure Sensor G410, Checking

Special tools, testers and auxiliary items required
- Multimeter
- wiring diagram

Test requirements
- Fuel Pump (FP) Control Module J538 OK.
- The Motronic Engine Control Module (ECM) J623 fuses OK.
- The fuel filter OK.
- The battery voltage at least 12.5 V.
- All electrical consumers switched off (radiator fan must NOT run during test).
- A/C switched off.
- The fuel tank at least 1/4 filled.
- The ignition switched off.

Test procedure
- Perform a preliminary check to verify the customers complaint. Preliminary Check

Start diagnosis
- Remove the engine cover with air filter.

Checking voltage







- Disconnect the Low Fuel Pressure Sensor G410 electrical harness connector - 1 -.
- Switch the ignition on.







- Using a multimeter, check the Low Fuel Pressure Sensor G410 electrical harness connector for voltage.

Low Fuel Pressure Sensor Specified value
G410 electrical
harness connector terminals
1 to Battery positive (+) Battery positive (+)
2 to Ground (GND) Battery positive (+)
3 to Ground (GND) about 5 V

- Switch the ignition off.

If specified value is obtained:
- Replace the Low Fuel Pressure Sensor G410

If the specified value was not 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.







- Using a Multimeter, check the Low Fuel Pressure Sensor G410 electrical harness connector terminals to the Motronic Engine Control Module (ECM) J623 electrical harness connector T60 terminals for an open circuit according to the wiring diagram.

Low Fuel Pressure Sensor Motronic Engine Control Module
G410 electrical harness (ECM) J623 electrical harness
connector terminals connector T60 terminals or test box sockets
1 14
2 7
3 37

Specified resistance 1.5 Ohms max.

If the specification is not obtained:
- Check the wiring for a 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 wiring connection.

If no malfunction is detected in the 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 not OK:
- Replace the Motronic 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