• | 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 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. 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.
The ignition is ON.
• | The primary fuel level signal on vehicles with dual tanks or the fuel level signal on vehicles with a single tank is greater than 4.5 volts. |
• | The above condition is present for greater than 20 seconds. |
• | The fuel gage defaults to empty. |
• | 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. |
Instrument Cluster Description and Operation
Control Module References for Scan Tool Information
Ignition ON, observe the scan tool Fuel Level Sensor parameter. The reading should be between 0.9-3.0 volts.
⇒ | If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage or 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.
• | Control Module References for ECM replacement, setup, and programming |