Circuit Description
The fuel level sensor changes resistance based on the fuel level. The body control module (BCM) monitors the signal circuit of the fuel level sensor in order to determine the fuel level. When the fuel tank is full, the fuel level sensor resistance is high and the BCM senses a high fuel level sensor signal voltage. When the fuel tank is empty, the fuel level sensor resistance is low and the BCM senses a low fuel level sensor signal voltage. The BCM uses the signal circuit of the fuel level sensor in order to calculate the total remaining fuel in the tank. The BCM sends the fuel level via the class 2 serial data circuit to the instrument panel cluster (IPC) in order to control the fuel gage.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
| • | The fuel level sensor signal is less than 0.15 volts. |
| • | The above condition is present for greater than 10 seconds. |
Action Taken When the DTC Sets
| • | The fuel gage defaults to empty. |
| • | The FUEL LEVEL LOW message illuminates in the driver information center. |
Conditions for Clearing the DTC
| • | The DTC becomes history when the conditions for setting the DTC are no longer present. |
| • | The history DTC clears after 40 malfunction free warm-up cycles. |
| • | The BCM receives the clear code command from the scan tool. |
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Instrument Cluster Schematics | ||||
1 | Did you perform the Instrument Cluster Diagnostic System Check? | -- | Go to Step 2 | |
2 |
Does the Fuel Level parameter display the specified value? | 0 L (0 gal) | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems |
3 |
Does the Fuel Level parameter display the specified value? | 76 L (20 gal) | Go to Step 5 | Go to Step 4 |
4 | Test the signal circuit of the fuel level sensor for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 6 |
5 | Test the signal circuit of the fuel level sensor for a short to ground between C415 and the fuel level sensor. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 7 |
6 | Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 8 |
7 | Inspect for poor connections at the harness connector of the fuel level sensor. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 9 |
8 | Replace the BCM. Refer to Body Control Module Replacement in Body Control System. Did you complete the replacement? | -- | Go to Step 10 | -- |
9 | Replace the fuel level sensor. Refer to Fuel Level Sensor Replacement in Engine Controls - 4.6L. Did you complete the replacement? | -- | Go to Step 10 | -- |
10 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
