Pinpoint Test Ai: The Check Fuel Cap Message Is Inoperative/Always On

WARNING: This page is about a different car, the 2009 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.

AI1 RETRIEVE THE RECORDED DTCs FROM BOTH CONTINUOUS AND ON-DEMAND PCM SELF-TESTS
- Check for recorded PCM DTCs from the continuous and on-demand self-tests.
- Is DTC P0457 recorded?
1. YES : If the CHECK FUEL CAP message is displayed, REFER to the Introduction - Gasoline Engines .
  If the CHECK FUEL CAP message is not displayed, go to AI2.
2. NO : If the CHECK FUEL CAP message is always displayed, go to AI3.
  If the CHECK FUEL CAP message is not displayed, the system is operating normally at this time. If the fuel cap was left off and the check fuel cap warning indicator did not turn on, driving conditions may not have allowed for the PCM to run the cruise test and message the instrument cluster (IC) to turn on the check fuel cap warning indicator.
AI2 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect all the PCM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
1. YES : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS . TEST the system for normal operation.
2. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
AI3 CHECK FOR CORRECT INSTRUMENT CLUSTER (IC) OPERATION
- Disconnect the instrument cluster (IC) connector.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect the instrument cluster (IC) connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
1. YES : INSTALL a new instrument cluster (IC). REFER to Instrument Cluster (IC) . TEST the system for normal operation.
2. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.