P0451

DTC P0451
Fuel tank pressure sensor fault Drive cycle C:Signal implausible.

Possible causes by suggested order of priority:
- Fuel tank pressure sensor fault.
- Open circuit C132/3 (GK) to C637/14 (GK).
- Open circuit C132/2 (RB) to C636/6 (RB).
- 5V sensor supply voltage C132/1 (R).
- Connectors C132, ECM C636 (B), ECM C637 (B).

Fuel tank pressure sensor fault.
CHECK THE FOLLOWING:
- Sensor pipe to fuel tank or vent port to open air are not blocked.
- Open circuit, voltage or connector problems are not present
- Check sensor by substitution with a known good unit.
POSSIBLE FAULTS
- Faulty pressure sensor .
- Pressure sensor vacuum or reference ports blocked.

Open circuit C132/3 (GK) to C637/14 (GK).
- Check resistance > 1M Ohm

Open circuit C132/2 (RB) to C636/6 (RB).
- Check resistance > 1M Ohm

5V sensor supply voltage C132/1 (R).
CHECK THE FOLLOWING:
- 5V sensor supply voltage C132/1 (R)..
Between 4.5V and 5.5V.
DIAGNOSTIC HINTS
- If the voltage is too high a short circuit to battery or faulty ECM should be suspected.
- If the voltage is too low an open circuit or connector problem should be suspected.

Connectors C132, ECM C636 (B), ECM C637 (B).
- Check for connector not correctly latched, backed out pins, damaged pins, corroded pins.