Fault Conditions

P1641

Fuel Pump Relay. No Voltage to Fuel Pump and O2S Preheating.







Fault symptoms
- Engine will not start.
- CHECK ENGINE.
- Misfiring before trouble code generated.

On-Board Diagnostics

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

Enable criteria:
- Engine running. Main relay voltage exceeding 10 V. O2S 1 and O2S 2 preheating active.

Fault criteria:
- More than 15 misfires. O2S 1 and O2S 2 preheating current below 10 mA for more than 1.5 s.

Dependents:
- None.

System reaction to a fault:
- None.

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

Fault handling: (For more information, )

- Type III.

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.

For more information,

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 - I