U1421

U1421-IMPLAUSIBLE IGNITION KEY OFF TIME RECEIVED

For complete wiring diagrams refer to Diagrams/Electrical.


- When Monitored:

Ignition on.

- Set Condition:

The fuel volume message the ECM is receiving is implausible. The circuit is continuously monitored. One Trip fault.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.


Theory of Operation

The Totally Integrated Power Module (TIPM) isn't receiving a fuel volume signal over CAN B from the Cluster Module. The TIPM has to send the PCM a fuel volume signal over CAN C. The signal the TIPM sends over CAN C is implausible.

Diagnostic Test


1. ACTIVE DTC

Ignition on, engine not running.

With a scan tool read DTCs.

Is the DTC Active at this time?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

2. CAN B BUS HARDWARE DTCS ALSO ACTIVE

With a scan tool check for DTCs in the TIPM.

Are any CAN B Hardware related DTCs active at this time?

Yes

- Refer to Communications for the appropriate diagnostic procedures.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Replace and program the Powertrain Control Module.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test