U1403

U1403-IMPLAUSIBLE FUEL LEVEL SIGNAL RECEIVED





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

Theory of Operation

The Totally Integrated Power Module isn't receiving a fuel volume signal from the Fuel Level Sensor. The PCM received the Fuel Level signal from the TIPM over the CAN C Bus circuit. The signal the TIPM is sending over CAN C is implausible.

- When Monitored:
Ignition on.

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





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

1. ACTIVE DTC
1. Ignition on, engine not running.
2. 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 Test

2. CAN C HARDWARE DTCS ALSO ACTIVE
1. With a scan tool check for DTCs in the TIPM.

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

Yes

- Testing and Inspection for the appropriate diagnostic procedures.
- Perform BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 3

3. FUEL LEVEL SENSOR




1. Turn the ignition off.
2. Disconnect the Fuel Pump Module harness connector.
3. Ignition on, engine not running.
4. Using a fused jumper wire, jump the (K900) Sensor Ground circuit to the (N4) Fuel Level Sensor No.1 Signal circuit in the Fuel Pump Motor harness connector.

Did the Fuel gauge level change from empty to full?

Yes

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

No

- Go To 4

4. (N4) FUEL LEVEL SIGNAL CIRCUIT OPEN




1. Turn the ignition off.
2. Disconnect the C7 TIPM harness connector.
3. Measure the resistance of the (N4) Fuel Level Signal circuit from the Fuel Pump Module harness connector to the C7 TIPM 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. (N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT




1. Measure the resistance between the (N4) Fuel Level Signal circuit and the (K900) Sensor Ground circuit from the Fuel Pump Module harness connector.

Is the resistance below 5.0 ohms?

Yes

- Repair the short between the (K900) Sensor Ground circuit and the (N4) Fuel Level Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 6

6. (K900) SENSOR GROUND CIRCUIT OPEN




1. Disconnect the C2 PCM harness connector.

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install PCM Pinout Box 8815 to perform diagnosis.

2. Measure the resistance of the (K900) Sensor Ground circuit from the Fuel Pump Module harness connector to the TIPM harness connector.

Is the resistance below 5.0 ohms?

Yes

- Go To 7

No

- Repair the open in the (K900) Sensor Ground circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

7. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connector at the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Powertrain Control Module connectors.
4. Search for 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 the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.