Conditions

Fuel Pump Relay Coil Circuit. Open / Short to Ground.





Fault symptoms
- Engine will not start.
- Misfiring can occur before trouble code is generated.

On-Board Diagnostics

Type of diagnosis:
- Continuous. But interrupted when fault criteria fulfilled and will not restart until next driving cycle.

Enable criteria:
- Ignition in ON position. Main relay voltage exceeding 10V. Output not active.

Fault criteria:
- Output voltage below 2V for more than 1 s.

Dependents:
- None.

System reaction to a fault:
- None.

OK report:
- Enable criteria fulfilled and fault criteria not fulfilled within 60 s.

- Type III. CHECK ENGINE does not go on.

Diagnostic help
Fault diagnosis concerns electrical fault in connecting leads or in the relay.

Functions in the diagnostic tool related to the fault:
- Activate fuel pump relay output.

Checking the wiring
Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short circuits. Observe the multimeter, diagnostic tool or test lamp during the check.

Proceed to Diagnostic Procedures Checking the Relay Power Supply