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 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.
- When Monitored:
With the ignition on, battery voltage between 9 and 16 volts, and engine run time greater than 3 seconds.
- Set Condition:
The fuel volume message the PCM is receiving is implausible. The circuit is continuously monitored. One Trip fault.
1. ACTIVE DTC
NOTE: For vehicle communication problems, use the scan tool to refer to the Network Review Screen. The screen depicts a high level view of the vehicle network. Fault and problem areas appear in red. Selecting any of the network components allows access to the source of the problem.
NOTE: Diagnose and repair any related sensor or communication DTCs in the Instrument Cluster (CCN) before continuing with this test.
1. Start the engine and allow it to reach operating temperature.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hand near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in possible serious or fatal injury.
2. With a scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go To 2
No
- Refer to the CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. Checking for an Intermittent DTC.
2. CAN B BUS HARDWARE DTCS ALSO ACTIVE
1. With a scan tool check for DTCs in the TIPM.
Are any CAN B Hardware related DTCs active at this time?
Yes
- Testing and Inspection for diagnostic procedures and for further possible causes.
- Perform the 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 electrical harness connector.
3. Ignition on, engine not running.
4. Connect a jumper wire between the (N4) Fuel Level Signal circuit and the (Z210) Ground circuit in the Fuel Pump Module harness connector.
5. 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 Pump Module.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.
No
- Go To 4 NOTE: Remove the jumper wire before continuing.
4. (N4) FUEL LEVEL SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Cluster harness connector.
3. 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 or high resistance in the (N4) Fuel Level Signal circuit.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.
5. (Z210) GROUND CIRCUIT OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (Z210) Ground circuit from the Fuel Pump Module harness connector to the Cluster harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 6
No
- Repair the open or high resistance in the (Z210) Ground circuit.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.
6. 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 PCM VERIFICATION TEST. PCM Verification Test.
No
- Replace and program the Powertrain Control Module.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.