U1403

U1403-IMPLAUSIBLE FUEL LEVEL SIGNAL RECEIVED





For a complete wiring diagram Refer to Diagrams/Electrical.


- When Monitored:
Ignition on.

- Set Condition:
The fuel volume message the PCM is receiving is implausible. The circuit is continuously monitored. One Trip fault.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Initial Inspection and Diagnostic Overview .

Theory of Operation


The Totally Integrated Power Module 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, select View�DTCs.
Is the DTC Active at this time?

Yes


- Go To 2


No


- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition



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


- Diagnose and repair the active DTC(s).
- Perform BODY VERIFICATION TEST - VER 1.Body Verification Test


No


- Go To 3



3. FUEL LEVEL SENSOR




Turn the ignition off.
Disconnect the Fuel Pump Module electrical harness connector.
Ignition on, engine not running.
Connect a jumper wire between the (N4) Fuel Level Signal circuit and the (Z210) Ground circuit in the Fuel Pump Module harness connector.
With the scan tool, read the Fuel Level Sensor voltage.
Did the Fuel Level Sensor voltage change from above 4.8 volts to below 0.4 of a volt with the jumper wire installed?

Yes


- Replace the Fuel Level Sensor.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test


No


- Go To 4

NOTE: Remove the jumper wire before continuing.




4. (N4) FUEL LEVEL SIGNAL CIRCUIT OPEN




Turn the ignition off.
Disconnect the C4 Cluster harness connector.
Measure the resistance of the (N4) Fuel Level Signal circuit from the Fuel Pump Module harness connector to the C4 Cluster harness connector.
Is the resistance below 5.0 ohms?

Yes


- Go To 5


No


- Repair the open in the (N4) Fuel Level Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test



5. (Z210) GROUND CIRCUIT OPEN




Disconnect the C3 Cluster harness connector.
Measure the resistance of the (Z210) Ground circuit from the Fuel Pump Module harness connector to the C3 Cluster harness connector.
Is the resistance below 5.0 ohms?

Yes


- Go To 6


No


- Repair the open in the (Z210) Ground circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test



6. POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connector at the Powertrain Control Module (PCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Powertrain Control Module connectors.
Refer to any Technical Service Bulletins that may apply.
Were there any problems found?

Yes


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


No


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