FUEL SENSOR FAULTED LOW (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 goes below 0.0196 of a volt for more than 90 seconds.
| Possible Causes |
| FUEL LEVEL SENSOR VOLTAGE BELOW 0.0196 OF A VOLT |
| FUEL LEVEL SENSOR |
| (N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO GROUND |
| (N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT |
| PCM |
Diagnostic Test
1. FUEL LEVEL SENSOR VOLTS BELOW 0.0196 VOLTIgnition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
With the scan tool, read the Fuel Level Sensor voltage.
Is the Fuel Level Sensor voltage below 0.0196 of a volt?
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 harness connector.
Ignition on, engine not running.
With the scan tool, read the Fuel Level Sensor voltage.
Did the Fuel Level Sensor voltage change from below 0.4 of a volt to above 4.0 volts?
Yes
- Replace the Fuel Level Sensor in accordance with the Service Information.
- 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 7
Diesel
- Go To 10
4. (N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the C2 and C3 PCM harness connectors.
Measure the resistance between ground and the (N4) Fuel Level Signal circuit at the Fuel Level Sensor harness connector.
Is the resistance below 100 ohms?
Yes
- Repair the short to ground 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 SHORTED TO THE (K900) SENSOR GROUND
Measure the resistance between the (N4) Fuel Level Signal circuit and the (K900) Sensor ground circuit at the Fuel Pump Module harness connector.
Is the resistance below 5.0 ohms?
Yes
- Repair the short between the (K900) Sensor ground and the (N4) Fuel Level Signal circuit.
- Perform POWERTRAIN VERIFICATION TEST VER - 5. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go To6
6. 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)
7. (N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the BCM C2 harness connectors.
Measure the resistance between ground and the (N4) Fuel Level Signal circuit at the Fuel Level Sensor harness connector.
Is the resistance below 100 ohms?
Yes
- Repair the short to ground in the (N4) Fuel Level Signal circuit.
- Perform BODY VERIFICATION TEST VER - 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
No
- Go To8
8. (N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO THE (K310) SENSOR GROUND
Measure the resistance between the (N4) Fuel Level Signal circuit and the (K310) Sensor ground circuit at the Fuel Pump Module harness connector.
Is the resistance below 5.0 ohms?
Yes
- Repair the short between the (K310) Sensor ground and 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. 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)
10. (K304) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the BCM C2 harness connectors.
Measure the resistance between ground and the (K304) Fuel Level Signal circuit at the Fuel Level Sensor harness connector.
Is the resistance below 100 ohms?
Yes
- Repair the short to ground in the (K304) Fuel Level Signal circuit.
- Perform BODY VERIFICATION TEST VER - 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
No
- Go To11
11. (K304) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO THE (K300) SENSOR GROUND
Measure the resistance between the (K304) Fuel Level Signal circuit and the (K300) Sensor ground circuit at the Fuel Pump Module harness connector.
Is the resistance below 5.0 ohms?
Yes
- Repair the short between the (K300) Sensor ground and the (N304) Fuel Level Signal circuit.
- Perform BODY VERIFICATION TEST VER - 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
No
- Go To12
12. 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 BODY VERIFICATION TEST VER - 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)