• | 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 | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
Fuel Level Sensor Signal | P0462 | 1 | P0463, P0464 | P0463 | P0461 |
Fuel Level Sensor Low Reference | -- | 1 | P0463, P0464 | P0463 | P0461 |
1. Fuel Gage Inaccurate or Inoperative |
The engine control module (ECM) monitors the signal circuit of the fuel level sender in order to determine fuel level. The fuel level sender consists of a variable resistor that changes resistance based on the fuel level in the tank. The ECM monitors the voltage across the sender resistance in order to determine the fuel level. When the fuel tank is full, the resistance of the fuel level sender is low and the ECM senses a low signal voltage on the signal circuit. When the fuel tank is empty, the resistance of the fuel level sender is high and the ECM senses a high signal voltage. The ECM uses the signal circuit of the fuel level sender in order to calculate the total remaining fuel, in percent. The ECM sends the fuel level percent via the serial data circuit to the instrument cluster in order to control the fuel gage.
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 refueling event. A refueling event test is executed to confirm that a refueling event has occurred. If refueling is confirmed, the test is considered passing. 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 greater than 30 seconds. |
• | DTC P0442 is aborted. |
• | The ECM records the operating conditions at the time the diagnostic 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. |
Instrument Cluster Description and Operation
Control Module References for scan tool information
⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuits tests normal, replace the ECM. |
⇒ | If not within the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | 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 4.2L engine |
• | Fuel Level Sensor Replacement for the 4.8L, 5.3L, 6.0L, 6.2L or 7.0L engines |
• | Control Module References for the ECM replacement, setup, and programming |