FUEL SENSOR FAULTED HIGH (BCM)
For a complete wiring diagram Refer to Section 8W
- When Monitored:
Ignition on and battery voltage above 10.4 volts.
- Set Condition:
The fuel level sensor signal voltage at the PCM goes above 4.9 volts for more than 90 seconds.
| Possible Causes |
| FUEL LEVEL SENSOR VOLTAGE ABOVE 4.9 VOLTS |
| FUEL LEVEL SENSOR |
| (N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE |
| (N4) FUEL LEVEL SIGNAL CIRCUIT OPEN |
| (K900) SENSOR GROUND CIRCUIT OPEN |
| PCM |
Diagnostic Test
1. FUEL LEVEL SENSOR VOLTAGE ABOVE 4.9 VOLTSIgnition on, engine not running.
With the scan tool, read the Fuel Level Sensor voltage.
Is the Fuel Level Sensor voltage above 4.9 volts?
Yes
- Go To2
No
- Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure).
- Perform POWERTRAIN VERIFICATION TEST VER - 5. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2. FUEL LEVEL SENSOR
Turn the ignition off.
Disconnect the Fuel Pump Module electrical harness connector.
Connect a jumper wire between the (N4) Fuel Level Signal circuit and the (K900) Sensor ground circuit at the Fuel Pump Module harness connector.
Ignition on, engine not running.
With the scan tool, read the Fuel Level Sensor voltage.
NOTE: Remove the jumper wire before continuing.
Did the Fuel Level Sensor voltage change from above 4.8 volts to below 0.4 of a volt?
Yes
- Replace the Fuel Level Sensor.
- Perform POWERTRAIN VERIFICATION TEST VER - 5. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go To3
3. DETERMINE VEHICLE ENGINE TYPE
What type of engine is the vehicle equipped with?
Gas
- Go To 4
Gas (ESP)
- Go To 8
Diesel
- Go To 12
4. (N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the C2 and C3 PCM harness connectors.
WARNING: When the engine is operating, do not stand in a direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing.
Ignition on, engine not running.
Measure the voltage on the (N4) Fuel Level Signal circuit at the Fuel Pump Module harness connector.
Is the voltage above 5.3 volts?
Yes
- Repair the short to voltage in the (N4) Fuel Level Signal circuit.
- Perform POWERTRAIN VERIFICATION TEST VER - 5. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go To5
5. (N4) FUEL LEVEL SIGNAL CIRCUIT OPEN
Turn the ignition off.
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 miller special tool #8815 to perform diagnosis.
Measure the resistance of the (N4) Fuel Level Signal circuit from the Fuel Pump Module harness connector to the appropriate terminal in Miller Special Tool #8815.
Is the resistance below 5.0 ohms?
Yes
- Go To6
No
- Repair the open in the (N4) Fuel Level Signal circuit.
- Perform POWERTRAIN VERIFICATION TEST VER - 5. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
6. (K900) SENSOR GROUND CIRCUIT OPEN
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 Miller Special Tool #8815 to perform diagnosis.
Measure the resistance of the (K900) Sensor ground circuit from the Fuel Pump Module harness connector to the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?
Yes
- Go To7
No
- Repair the open in the (K900) Sensor ground circuit.
- Perform POWERTRAIN VERIFICATION TEST VER - 5. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
7. 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.
If there are no possible causes remaining, view repair.
Repair
- Replace and program the Powertrain Control Module per Service Information.
- Perform POWERTRAIN VERIFICATION TEST VER - 5. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
8. (N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED BATTERY TO VOLTAGE
Turn the ignition off.
Disconnect the BCM C2 harness connectors.
Ignition on, engine not running.
Measure the voltage on the (N4) Fuel Level Signal circuit at the Fuel Pump Module harness connector.
Is the voltage above 5.3 volts?
Yes
- Repair the short to voltage in the (N4) Fuel Level Signal circuit.
- Perform BODY VERIFICATION TEST VER -1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
No
- Go To9
9. (N4) FUEL LEVEL SIGNAL CIRCUIT OPEN
Turn the ignition off.
Measure the resistance of the (N4) Fuel Level Signal circuit from the Fuel Pump Module harness connector to the appropriate terminal in Miller Special Tool #8815.
Is the resistance below 5.0 ohms?
Yes
- Go To10
No
- Repair the open in the (N4) Fuel Level Signal circuit.
- Perform BODY VERIFICATION TEST VER - 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
10. (K310) SENSOR GROUND CIRCUIT OPEN
Measure the resistance of the (K310) Sensor ground circuit from the Fuel Pump Module harness connector to the appropriate terminal of Miller Special Tool #8815.
Is the resistance below 5.0 ohms?
Yes
- Go To11
No
- Repair the open in the (K310) Sensor ground circuit.
- Perform BODY VERIFICATION TEST VER - 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
11. BCM
NOTE: Before continuing, check the BCM 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.
If there are no possible causes remaining, view repair.
Repair
- Replace and program the Body Control Module per Service Information.
- Perform BODY VERIFICATION TEST VER - 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
12. (N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the BCM C2 harness connectors.
Ignition on, engine not running.
Measure the voltage on the (N4) Fuel Level Signal circuit at the Fuel Pump Module harness connector.
Is the voltage above 5.3 volts?
Yes
- Repair the short to voltage in the (N4) Fuel Level Signal circuit.
- Perform BODY VERIFICATION TEST VER - 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
No
- Go To13
13. (K304) FUEL LEVEL SIGNAL CIRCUIT OPEN
Turn the ignition off.
Measure the resistance of the (K304) Fuel Level Signal circuit from the Fuel Pump Module harness connector to the appropriate terminal in Miller Special Tool #8815.
Is the resistance below 5.0 ohms?
Yes
- Go To14
No
- Repair the open in the (K304) Fuel Level Signal circuit.
- Perform BODY VERIFICATION TEST VER - 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
14. (K300) SENSOR GROUND CIRCUIT OPEN
Measure the resistance of the (K300) Sensor ground circuit from the Fuel Pump Module harness connector to the appropriate terminal of Miller Special Tool #8815.
Is the resistance below 5.0 ohms?
Yes
- Go To15
No
- Repair the open in the (K300) Sensor ground circuit.
- Perform BODY VERIFICATION TEST VER - 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
15. BCM
NOTE: Before continuing, check the BCM 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.
If there are no possible causes remaining, view repair.
Repair
- Replace and program the Body Control Module per Service Information.
- Perform BODY VERIFICATION TEST VER - 1 (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE) .