Diagnostic Instructions
Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Diagnostic Fault Information
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
|---|---|---|---|---|---|
Fuel Level Sensor Signal Circuit | P0462 | 1 | P0463 P0464 | P0463 | P0461 |
Fuel Level Sensor Low Reference Circuit | -- | 1 | P0463 P0464 | P0463 | P0461 |
1. Fuel Gage Inaccurate or Inoperative | |||||
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 level percentage via the GMLAN serial data circuit to the body control module (BCM). The BCM sends the fuel information to the instrument panel cluster via the GMLAN serial data circuit in order to control the fuel gage and display the fuel level. The fuel information is also used for misfire and evaporative emission (EVAP) diagnostics.
Reference Information
Schematic Reference
| • | Engine Controls Schematics for the 2.4L engine |
Connector End View Reference
| • | Engine Control Module Connector End Views for the 2.4L engine |
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Ignition OFF, disconnect the fuel level sensor connector, install a signal generator and instrument panel tester between the signal circuit and the low reference circuit.
- Ignition ON, vary the resistance on the signal generator from 40 ohms - 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.
- Ignition ON, vary the resistance on the signal generator from 40 ohms - 250 ohms. Observe the fuel gage and verify that the fuel gage displays the correct fuel level. Refer to Fuel Level Specifications.
- If all circuits test normal, test or replace the fuel level sensor.
| ⇒ | 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. |
| ⇒ | If the fuel gage display is incorrect, test or replace the fuel gage. |
Component Testing
Measure the resistance of the float arm of the fuel level sender while moving the float arm between 40-250 ohms.
Repair Instructions
Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Fuel Level Sensor Replacement for the 2.4L engine |
| • | Control Module References for the ECM and IPC replacement, setup, and programming |
