P0457

P0457-LOOSE FUEL CAP

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation










Fuel level is recorded when the ignition key is turned off and is compared to the fuel level when the ignition key is turned back on. The Powertrain Control Module (PCM) recognizes an increase in fuel level and will fail the Large leak test because the fuel cap is broken or not installed properly. GAS CAP will be displayed to inform the owner that the cap is off of loose.

- When Monitored:
Engine running. Ambient Temperature between 4° C and 35° C (40° F and 95° F) Close Loop fuel system. Test runs after failing the large leak size test as inconclusive and the PCM has sensed a fuel increase.

- Set Condition:
If a leak greater than.090" is detected by the Powertrain Control Module (PCM) for three consecutive cold start trips after a significant fuel level change, this DTC will set. One good trip turns off the MIL.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. PCM Pre-Diagnostic Troubleshooting Procedure.

Diagnostic Test

1. ACTIVE DTC

NOTE: If DTC P0455-EVAP SYSTEM LARGE LEAK is set along with this DTC, perform the DTC P0455 diagnostic procedure before continuing with this test.

1. Using the scan tool, perform the ESIM FORCED MONITOR TEST. Allow the test to complete.
2. Using the scan tool, read DTCs.

Is the DTC Active or Pending at this time?

Yes

- Go To 2

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals and correct pin tension.
- Perform the INTERMITTENT CONDITION diagnostic procedure. PCM Intermittent Condition Test.

2. FUEL FILLER CAP VISUAL INSPECTION
1. Remove the Fuel Filler Cap and visually inspect for the following:

- Loose or missing Fuel Filler Cap or seal
- Damaged locking tabs on the Fuel Filler Cap and/or filler tube
- Damaged seal points on the Fuel Filler Cap and/or filler tube

Were any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 3

3. FUEL FILLER CAP
1. Reinstall the Fuel Filler Cap.
2. Using the scan tool, perform the ESIM FORCED MONITOR TEST. Allow the test to complete.
3. Using the scan tool, read DTCs.

Is the DTC Active or Pending at this time?

Yes

- Replace the Fuel Filler Cap.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals and correct pin tension.
- Perform the INTERMITTENT CONDITION diagnostic procedure. PCM Intermittent Condition Test.