Circuit Description
The Fuel Level Sensor changes resistance based on fuel level. The Fuel Level Sensor has a signal circuit and a ground circuit. The PCM applies a voltage (about 5.0 volts) on the signal circuit to the sensor. The PCM monitors changes in this voltage caused by changes in the resistance of the sensor to determine fuel level.
When the fuel tank is full, the sensor resistance is high, therefore, the PCM will sense a high signal voltage (fuel tank full). When the fuel tank is empty, the sensor resistance is low, and the PCM senses a low signal voltage (fuel tank empty).
The PCM uses inputs from the Fuel Level Sensor to calculate the total fuel remaining in the fuel tank. This information is then sent to the fuel gauge via the class 2 circuit. The Fuel Level information is also used for misfire and EVAP diagnostics.
This DTC sets when the PCM senses a signal voltage lower than the normal operating range of the sensor.
Conditions for Running the DTC
| • | The ignition is ON. |
| • | The system voltage is between 11 and 16 volts. |
Conditions for Setting the DTC
Fuel level sensor reading is less than 3.5 percent for more than 25 seconds.
Action Taken When the DTC Sets
| • | The PCM will record the operating conditions during the time which the diagnostic fails. This information will store in the Failure Records. |
| • | A history DTC is stored. |
Conditions for Clearing the DTC
| • | A history DTC clears after 40 consecutive warm up cycles without a fault. |
| • | The scan tool clears the DTC. |
Test Description
The numbers below refer to the step numbers on the Diagnostic Table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check ? | -- | ||
Is the fuel level sensor percentage below the specified value? | 3.5% | |||
3 |
Does the DTC fail this ignition? | -- | Go to Intermittent Conditions | |
4 |
Is the fuel level sensor percentage at the specified value? | 100% | ||
5 | Test the signal circuit of the fuel level sensor for a short to ground . Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
6 | Replace the fuel level sensor. Refer to Fuel Sender Assembly Replacement . Did you complete the replacement? | -- | -- | |
7 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the replacement? | -- | -- | |
8 |
Does the DTC run and Pass? | -- | ||
9 | Select the Capture Info option and the Review Info option using the scan tool. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to the applicable DTC | System OK |
