Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
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 1 | P0463 | P0461 |
Fuel Level Sensor Low Reference Circuit | -- | P0463 1 | P0463 | P0461 |
1. Fuel Gage Inaccurate or Inoperative |
The fuel level sensor changes resistance in response to the fuel level. The engine control module (ECM) 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 senses a low signal voltage. When the fuel tank is empty, the sensor resistance is high and the ECM senses a high signal voltage. The ECM uses the signal circuit of the fuel level sensor in order to calculate the percentage of remaining fuel in the tank. The ECM sends the fuel level percentage via GMLAN serial data circuit to the instrument cluster in order to control the fuel gage. The fuel information is also used for misfire and evaporative emission (EVAP) diagnostics.
The engine is running.
The ECM does not detect a change in fuel level of at least 1.6 percent over a distance of 193 km (120 miles).
• | The fuel gage defaults to empty. |
• | The low fuel indicator illuminates. |
• | The ECM records the operating conditions at the time that the diagnostic test fails. The ECM 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. |
• | The ECM receives a clear code command from the scan tool. |
⇒ | Repair any fuel level sender interference. |
Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for the ECM replacement, setup and programming |