XL-7 2WD V6-3.6L (2007)
Fuel Gauge: Testing and Inspection
Fuel Gage Inaccurate or Inoperative
Diagnostic Fault Information
Perform the [Diagnostic System Check - Vehicle Diagnostic Information] prior to using this diagnostic procedure. See: Testing and Inspection/Initial
Inspection and Diagnostic Overview/Diagnostic System Check - Vehicle Diagnostic Information
Circuit/System Description
The fuel level sender changes resistance based on the fuel level. The engine control module (ECM) 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 ECM senses a low signal voltage. When the fuel tank is
empty, the sender resistance 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 percent in the tank. The ECM sends the fuel level message via the serial data circuit to the body control module (BCM).
The BCM sends the fuel level percent to the instrument panel cluster (IPC) via the serial data circuit to display on the fuel gage. The fuel level
information is also used for misfire and evaporative emission (EVAP) diagnostics.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the fuel level sensors. 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 to 250 ohms. Verify that the scan tool Fuel Tank Level Remaining parameter
displays the correct fuel level percent.
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If the fuel level percent is incorrect, test the signal circuit and the low reference circuit for an open/high resistance. If the circuits test normal,
replace the ECM.
3. Ignition ON, vary the resistance on the signal generator from 40 to 250 ohms and monitor the fuel gage.
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If the gage is incorrect, replace the IPC.
4. If all circuits test normal, test or replace the fuel level sensors.
Component Testing
Measure the resistance of the float arm of the fuel level sender while moving the float arm between 40-250 ohms.
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If the resistance does not move smoothly across the specified range, replace the fuel level sensor.
Repair Instructions
Perform the [Diagnostic Repair Verification - Vehicle Diagnostic Information] after completing the diagnostic procedure. See: Testing and
Inspection/Diagnostic Trouble Code Tests and Associated Procedures
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[Primary Fuel Tank Module Replacement]
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[Secondary Fuel Tank Module Replacement]
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[Control Module References] for ECM or IPC replacement, setup, and programming. See: Testing and Inspection/Programming and Relearning
