U1403

U1403-IMPLAUSIBLE FUEL LEVEL SIGNAL RECEIVED





For a complete wiring diagram refer to Diagrams/Electrical.


Theory of Operation


The TIPM has to send the PCM a fuel level signal over CAN C. The signal the TIPM sends 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.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.


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 C BUS DTCS ALSO ACTIVE

With a scan tool check for DTCs in the TIPM.

Are any CAN C 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

- Go To 3


3. FUEL LEVEL SENSOR





Turn the ignition off.

Disconnect the Fuel Pump Module harness connector.

Ignition on, engine not running.

Using a fused jumper wire, jump the (K91) 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 SHORTED TO GROUND





Turn the ignition off.

Disconnect the C7 TIPM harness connector.

Measure the resistance between ground and the (N4) Fuel Level Signal circuit in the Fuel Pump Module harness connector.

Is the resistance below 100 ohms?

Yes

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

No

- Go To 5


5. (N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO THE (K91) SENSOR GROUND CIRCUIT





Measure the resistance between the (N4) Fuel Level Signal circuit and the (K91) Sensor Ground circuit from the Fuel Pump Module harness connector.

Is the resistance below 5.0 ohms?

Yes

- Repair the short between the (K91) Sensor Ground circuit and the (N4) Fuel Level Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 6


6. EXCESSIVE RESISTANCE IN THE (N4) FUEL LEVEL SIGNAL CIRCUIT





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 7

No

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

7. EXCESSIVE RESISTANCE IN THE (K91) SENSOR GROUND CIRCUIT





Disconnect the C1 TIPM harness connector.

Measure the resistance of the (K91) 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 8

No

- Repair the excessive resistance in the (K91) Sensor Ground circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

8. PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

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