Fuel Gauge Not Operating Properly

NOTE: Ensure fuel tank is not empty before proceeding with this test.

Turn ignition off. Press and hold trip button on instrument cluster while turning ignition on. If fuel gauge sweeps from empty to full then back to empty, go to next step. If fuel gauge does not sweep from empty to full then back to empty, replace instrument cluster.
Turn ignition off. Connect scan tool to Data Link Connector (DLC). Turn ignition on. Using scan tool, retrieve Body Control Module (BCM) DTCs. If no DTCs exist, go to next step. If any DTCs exist, perform appropriate test. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION table under SELF-DIAGNOSTIC SYSTEM.
Turn ignition on. If fuel gauge always shows empty, go to next step. If fuel gauge is always between full and empty, go to step 6 . If fuel gauge always shows full, go to step 7 .
Turn ignition off. Remove rear seat and disconnect left body harness connector C308. Turn ignition on. Using a fused jumper wire, ground terminal No. 2 (Dark Blue wire) at left body harness connector C308. See Figure . If fuel gauge now reads full, go to next step. If fuel gauge does not now read full, replace instrument cluster.
Check wiring between left body harness connector C308 and fuel pump module. If problem exists, repair wiring as necessary. If problem does not exist, replace fuel pump module.

NOTE: Manufacturer recommends measuring resistance in step 6) 2 times. Once with tank full, then removing 5 gallons and measuring resistance again.

Turn ignition off. Disconnect BCM harness connector C4. Measure resistance between ground and terminal No. 7 (Dark Blue wire) at BCM harness connector C4 with appropriate amount of fuel in fuel tank. See FUEL LEVEL SENSOR RESISTANCE table. See Figure . If resistance is not as specified, replace fuel pump module. If resistance is as specified, replace instrument cluster.
Turn ignition off. Remove rear seat and disconnect left body harness connector C308. Turn ignition on. Using scan tool, check fuel level voltage. If greater than 9 volts is displayed, go to next step. If 9 volts or less is displayed, go to step 10 .
Ensure left body harness connector C308 is still disconnected and ignition is on. If fuel gauge now reads empty, go to next step. If fuel gauge still reads full, replace instrument cluster.
Check wiring between left body harness connector C308 and fuel pump module. If problem exists, repair wiring as necessary. If problem does not exist, replace fuel pump module.
Turn ignition off. Disconnect Body Control Module (BCM) harness connector C4. Measure resistance between ground and terminal No. 7 (Dark Blue wire) at BCM harness connector C4. See Figure . If resistance is greater than 5 ohms, replace BCM. If resistance is 5 ohms or less, repair short to ground in Dark Blue wire between fuel pump module and BCM.

FUEL LEVEL SENSOR RESISTANCE