Fuel Pump Relay, Checking
Special tools and workshop equipment required
- Multimeter.
- wiring diagrams.
Test requirements
- Fuse -S163- OK.
- Load Reduction Relay -J59- OK.
- The Engine Control Module (ECM) - J220- Fuse -S229- and Fuse -S10- OK.
- The Ground (GND) connections at the engine and transmission OK.
- The battery voltage at least 12.5 V.
- The generator OK.
Test procedure
-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK .
Start diagnosis
-- Using a Multimeter, check the following wiring connection for voltage.
| Fuel Pump (FP) Relay -J17- socket | Measure to |
|---|---|
| 1/30 | Engine Ground (GND) |
Specified value: 12.5 V
If the specified value was not obtained:
-- Check the Fuel Pump (FP) Relay -J17- socket 1/30 to the Battery for an open circuit or short to Ground (GND).
-- Check the electrical harness connectors for damage, corrosion, loose or broken terminals.
-- If necessary, repair the wiring connection.
If no malfunctions are found in the wiring:
-- Using a Multimeter, check the following wiring connection for voltage.
| Fuel Pump (FP) Relay -J17- | Measure to |
|---|---|
| 3/86 | Engine Ground (GND) |
-- Crank the engine.
Specified value: 12.5 V
-- Switch the ignition off.
If the specified value was not obtained:
-- Check the Fuel Pump (FP) Relay -J17- socket 3/86 to the fuse SC 2 for an open circuit or short to Ground (GND).
-- Check the electrical harness connectors for damage, corrosion, loose or broken terminals.
-- If necessary, repair the wiring connection.
If no malfunctions are found in the wiring:
Checking Ground (GND)
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 wiper arms and plenum chamber cover. Refer to the appropriate service information.
-- Disconnect the Engine Control Module (ECM) -J220- electrical harness connector T121. Refer to the appropriate service information.
-- Using a Multimeter --, check the following wiring connection for resistance.
| Fuel Pump (FP) Relay -J17- socket | Motronic Engine Control Module (ECM) -J220- electrical harness connector T121 or test box socket |
|---|---|
| 4/85 | 65 |
Specified value: 1.5 Ω.
If the specified value was not obtained:
-- Check the Fuel Pump (FP) Relay -J17- socket 4/85 to the Motronic Engine Control Module (ECM) -J220- electrical harness connector T121 terminal 65 for an open circuit or a short to Battery (+).
-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
-- If necessary, repair the wiring connection.
If no malfunctions are found in the wiring and the voltage supply was OK:
-- Replace the Fuel Pump (FP) Relay -J17-.
-- Perform a road test to verify repair.
If the fault does not return:
Generate readiness code. Refer to READINESS CODE .
-- End of diagnosis.
If the fault does return and no malfunction is detected in the wiring and the voltage supply was OK:
-- Replace the Motronic Engine Control Module (ECM) -J220-. Refer to the appropriate service information.
-- Assembly is performed in the reverse of the removal.
Final procedures
After repair work, the following work steps must be performed in the following sequence:
- Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
- If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
- If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .