Test P

PINPOINT TEST P: THE CHECK FUEL CAP INDICATOR IS NEVER ON

Test P1:

Test P2-P3:

Normal Operation
The PCM monitors the fuel tank evaporative system for significant leaks that occur following refueling of the vehicle. If a fuel tank pressure change greater than a minus 23.7 kPa (7 in Hg) of vacuum within 30 seconds after refueling has occurred, or there is excessive purge (fuel vapor) flow greater than 454 g (0.06 lb) per minute, the PCM will set DTC P0457 and send a message to the instrument cluster over the CAN communication network, circuits 3125 (RD/YE) and 3126 (TN/YE), to turn on the CHECK FUEL CAP indicator.

Possible Causes
- fuel tank evaporative system
- PCM
- instrument cluster