• | 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 1 | P0463 | P0461 |
Fuel Level Sensor Low Reference Circuit | -- | P0463 P0464 1 | P0463 | P0461 |
1. Fuel Gage Inaccurate or Inoperative |
The fuel level sensor changes resistance in response to the fuel level. The 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 PCM senses a low signal voltage. When the fuel tank is empty, the sensor resistance is high and the PCM senses a high signal voltage. The PCM uses the signal circuit of the fuel level sensor in order to calculate the percentage of remaining fuel in the tank. The PCM sends the fuel level percentage via serial data circuit to the instrument cluster in order to control the fuel gage. The fuel information is also used for misfire, evaporative emission (EVAP), and other onboard diagnostics.
This diagnostic tests for an intermittent fuel level sender signal. If a change in fuel level is detected DTC P0442 is aborted due to a possible refueling event. A refueling event test is executed to confirm that a refueling event has occurred. If refueling is confirmed, the test for DTC P0464 is considered passing. The refueling event test must pass two out of three times, otherwise, the DTC will set indicating an intermittent signal problem.
• | The ignition is OFF. |
• | DTC P0442 is running. |
• | The fuel level change is greater than 10 percent. |
• | The above condition is present for less than 30 seconds. |
• | Both conditions above occur 2 out of 3 times as part of a refueling event test. |
• | DTC P0442 is aborted. |
• | The PCM records the operating conditions at the time the diagnostic fails. The 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. |
• | The PCM receives a clear code command from the scan tool. |
Using the Failure Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.
⇒ | If the fuel level voltage is incorrect, test the signal circuit and the low reference circuit for an open/high resistance. If the circuits test normal, replace the PCM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for PCM or IPC replacement, setup, and programming |