Operation CHARM: Car repair manuals for everyone.

Fuel Gage Inaccurate or Inoperative



Fuel Gage Inaccurate or Inoperative (2.4L and 2.2L)

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview






Circuit/System Description

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 information to the instrument panel cluster via the serial data circuit in order to control the fuel gage and display the fuel level. Then fuel information is also used for evaporative emission (EVAP) and OBD diagnostics.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the fuel level sensor. Install a signal generator and instrument panel tester between the signal circuit and the low reference circuit.
2. Ignition ON, vary the resistance on the signal generator from 40-250 ohms. With the scan tool verify that the Fuel Tank Level Remaining parameter displays the correct fuel level percent. Refer to Fuel Level Specifications.

If the fuel level percent is incorrect, test the signal circuit and the low reference circuit for an open/high resistance. If all circuit tests normal, replace the ECM.

3. Ignition ON, vary the resistance on the signal generator from 40-250 ohms. Observe the fuel gage and verify that the fuel gage displays the correct fuel level. Refer to Fuel Level Specifications.

If the fuel gage display is incorrect, test or replace the fuel gage.

4. If all circuits test normal, test or replace the fuel level sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

* Fuel Level Sensor Replacement for the 2.4L engine
* Fuel Level Sensor Replacement (RPO NT7) Fuel Level Sensor Replacement (RPO NU6) for the 2.2L engine.
* Control Module References for the ECM and IPC replacement, setup, and programming Verification Tests