Diagnostic Aids
WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Inaccurate readings will occur if resistance measurements are taken on a fuel tank pressure sensor. The fuel tank pressure sensor contains an internal amplifier circuit that requires applied voltage to function properly.
Fuel tank pressure sensor on scan tool should read 1.3-1.7 volts with ignition on, engine off and fuel cap removed. This represents atmospheric pressure or zero in. Hg.
DTC P0451 indicates that the fuel tank pressure sensor signal voltage is skewed high or low. Possible causes of DTC P0451:
- Corrosion in fuel tank in-line harness connector.
- Corrosion in fuel tank pressure sensor harness connector.
- Fuel tank pressure sensor skewed.