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Test B: Fuel Gauge Inaccurate/Inoperative: Notes

  1. If instrument cluster diagnostic system check has been performed, go to next step. If instrument cluster diagnostic system check has not been performed, perform instrument cluster diagnostic system check. See INSTRUMENT CLUSTER DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM.
    2. NOTE: Verify Signal Generator and Instrument Panel Tester (J-33431-C) resistance settings with a DVOM before testing system.
  2. Disconnect fuel sending 4-pin harness connector. Fuel sending unit is located in rear of vehicle. Connect Signal Generator and Instrument Panel Tester (J-33431-C) between fuel sending unit harness connector terminals "A" (Purple wire) and "B" (Black/White wire). Turn ignition switch to RUN position. Vary resistance on Signal Generator and Instrument Panel Tester (J-33431-C) from 40-250 ohms. If fuel gauge does not display proper fuel level, go to next step. See FUEL LEVEL SPECIFICATIONS  table. If fuel gauge displays proper fuel level, go to step  4 .
    FUEL LEVEL SPECIFICATIONS

    Gauge Display Fuel Level Percentage Ohms
    E 4-10 40-47
    1/4 31 90
    1/2 54 130
    3/4 74 164
    F 97-100 207-250
    Low Fuel Indicator On 7 45
    3. NOTE: Turn ignition switch to LOCK position momentarily between resistance settings to quickly update scan tool display.
  3. Turn ignition switch to LOCK position. Connect scan tool to Data Link Connector (DLC). DLC is located under instrument panel right of steering column. Turn ignition switch to RUN position. Vary resistance of Signal Generator and Instrument Panel Tester (J-33431-C) from 40-250 ohms. Using scan tool, observe FUEL TANK LEVEL REMAINING parameter in Powertrain Control Module (PCM) EVAP data list. If scan tool does not display correct fuel level percentage, go to step  5 . See FUEL LEVEL SPECIFICATIONS  table. If scan tool displays correct fuel level percentage, go to step  11 .
  4. Inspect fuel sending unit harness connector for poor connection or loose terminals, high resistance in Purple wire between PCM and fuel sending unit or high resistance in Black/White wire between PCM and fuel sending unit, misaligned fuel sending unit or deformed fuel tank. If problem still exists, go to step  7 . If problem does not exist, go to step  13 .
  5. Turn ignition switch to LOCK position. Disconnect PCM 80-pin harness connector C2. PCM is located under instrument panel, near steering column. Measure resistance in Purple wire between fuel sending unit harness connector terminal "A" and PCM harness connector C2 terminal No. 69. If resistance is less than 2 ohms, go to next step. If resistance is 2 ohms or more, repair open or high resistance in Purple wire between PCM and fuel sending unit. After repair, go to step  13 .
  6. Measure resistance in Black/White wire between fuel sending unit harness connector terminal "B" and PCM harness connector terminal No. 35. If resistance is less than 2 ohms, go to step  9 . If resistance is 2 ohms or more, repair open or high resistance in Black/White wire between PCM and fuel sending unit. After repair, go to step  13 .
  7. Remove fuel sending unit. Check for stuck fuel sending unit, fuel strainer interfering with sending unit float arm or foreign material in gas tank. If problem still exists, go to next step. If problem does not exist, go to step  13 .
  8. Measure resistance between terminals "A" and "B" at fuel sending unit (component side) while moving float arm. Resistance should change smoothly from 40-250 ohms. If resistance is as specified, go to DIAGNOSTIC AIDS  . If resistance is not as specified, go to step  10 .
  9. Inspect PCM harness connector for poor connections or loose terminals. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES - CARS article in ENGINE PERFORMANCE. If problem still exists, go to step  12 . If problem does not exist, go to step  13 .
  10. Replace fuel sending unit. After repair, go to step  13 .
  11. Replace instrument cluster. After repair, go to step  13 .
    12. NOTE: New PCM needs to be programmed. See appropriate COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION.
  12. Replace PCM. After repair, go to next step.
  13. Reconnect all disconnected components and connectors. Operate vehicle to verify repair. If problem does not exist, system is okay. If problem still exists, go to step  2 .
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