• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Fuel Level Sensor Reference Voltage Circuit | P0462 | -- | -- | P0461 |
Fuel Level Sensor Signal Circuit | P0462 | P0463 P0464 | P0463 | P0461 |
Fuel Level Sensor Low Reference Circuit | -- | P0463 P0464 | P0463 | P0461 |
The fuel level sensor changes resistance in response to the fuel level. The engine control module (ECM)/powertrain control module (PCM) monitors the signal circuit of the fuel level sensor in order to determine the fuel level. When the fuel tank is full, the sensor resistance is low and the ECM/PCM senses a low signal voltage. When the fuel tank is empty, the sensor resistance is high and the ECM/PCM senses a high signal voltage. The ECM/PCM uses the signal circuit of the fuel level sensor in order to calculate the percentage of remaining fuel in the tank. The ECM/PCM sends the fuel level percentage via serial data circuit to the body control module (BCM). The BCM sends serial data messages to the instrument panel cluster (IPC) in order to control the fuel gage.
The engine is running.
The ECM/PCM does not detect a change in fuel level of at least 1.6 percent over a distance of 193 km (120 mi).
• | The fuel gage defaults to empty. |
• | The low fuel indicator illuminates. |
• | The ECM/PCM records the operating conditions at the time that the diagnostic test fails. The ECM/PCM displays the failure information in the Failure Records on the scan tool. |
• | 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. |
• | Engine Controls Schematics for the 3.8L engine |
• | Engine Controls Schematics for the 4.6L engine |
• | Powertrain Control Module Connector End Views for the 3.8L engine |
• | Engine Controls Connector End Views for the 4.6L engine |
⇒ | Repair any fuel level sender interference. |
⇒ | If not within the specified range, replace the fuel level sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Fuel Level Sensor Replacement for the 4.6L engine |
• | Fuel Level Sensor Replacement for the 3.8L engine |
• | Control Module References for the ECM/PCM replacement, setup and programming |