• | 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 1 | P0463 | P0461 |
Fuel Level Sensor Low Reference Circuit | -- | P0463 1 | P0463 | P0461 |
1. Fuel Gage Inaccurate or Inoperative |
The fuel level sender changes resistance based on fuel level. The powertrain control module (PCM) monitors the signal circuit of the fuel level sender in order to determine fuel level. When the fuel tank is full, the sender resistance is low and the PCM senses a low signal voltage. When the fuel tank is empty, the sender resistance is high and the PCM senses a high signal voltage. The PCM uses the signal circuit of the fuel level sender in order to calculate the total remaining fuel percentage in the tank. The PCM sends the fuel level percent via the class 2 serial data circuit to the instrument cluster in order to control the fuel gage. The fuel level information is also used for misfire and evaporative emission (EVAP) diagnostics.
The ignition is ON.
• | The fuel level signal is less than 1 percent. |
• | The above condition is present for greater than 20 seconds. |
• | The fuel gage defaults to empty. |
• | The LOW FUEL indicator illuminates. |
• | 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 the clear code command from the scan tool. |
• | Engine Controls Schematics for the 2.9L engine |
• | Engine Controls Schematics for the 3.7L engine |
• | Powertrain Control Module Connector End Views for the 2.9L engine |
• | Powertrain Control Module Connector End Views for the 3.7L engine |
⇒ | If greater than 1.0 ohm, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the PCM. |
⇒ | If less than 98 percent, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the PCM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Fuel Level Sensor Replacement for the 2.9L engine |
• | Fuel Level Sensor Replacement for the 3.7L engine |
• | Control Module References for the PCM replacement, setup, and programming |