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Pinpoint Test D: Fuel Gauge & Low Fuel Warning Lamp System

NOTE: Go to TROUBLE SHOOTING  before starting pinpoint test. Identify system where problem is located. Find symptom in trouble shooting and go to specific pinpoint test step as directed by trouble shooting procedure.

  1. Check Fuse

    Check the 10A METER fuse located in the interior fuse panel. Is the fuse OK? If yes, go to step  4 If no, go to next step.

  2. Check System

    Turn key OFF. Replace the 10A METER fuse. Turn key ON. Inspect the fuse. Does the fuse fail again? If yes, go to next step. If no, go to step  4 .

  3. Check For Short To Ground

    Turn key OFF. Remove the instrument cluster. Disconnect the 10-pin and the black 12-pin instrument cluster connectors. Remove the 10A meter fuse. Measure the resistance of the (Gray/Blue) wire between the right terminal of the 10A meter fuse and ground. Is the resistance less than 5 ohms? If yes, service the (Gray/Blue) wire between the interior fuse panel and the instrument cluster. If no, install the 10A meter fuse. Go to next step. See WIRING DIAGRAMS  .

  4. Check Power Supply To Fuel Anti-Slosh/Low Fuel Warning Module &Fuel Gauge

    Turn key OFF. Remove the instrument cluster. Leave the instrument cluster connectors connected. Turn key ON. Measure the voltage on Terminal No. 2 of the fuel anti-slosh/low fuel warning (LFW) module connector. Measure the voltage on Terminal B of the fuel gauge. Are the voltages greater than 10 volts? If yes, go to step  6 . If no, go to next step.

  5. Check Power Supply To Instrument Cluster.

    Turn key OFF. Disconnect the 10-pin instrument cluster connector. Turn key ON. Measure the voltage on the (Gray/Blue) wire between Terminal No. 1D of the 10-pin instrument cluster connector and ground. Is the voltage greater than 10 volts? If yes, replace the instrument cluster printed circuit board. If no, service the (Gray/Blue) wire between the interior fuse panel and the instrument cluster. See WIRING DIAGRAMS  .

  6. Check Fuel Anti-Slosh/Low Fuel Warning Module & Fuel Gauge Ground

    Turn key OFF. Remove the instrument cluster. Leave the instrument cluster connectors connected. Measure the resistance of the (Black/White) wire between Terminal No. 3 of the fuel anti-slosh/LFW module and ground. Measure the resistance of the (Black/White) wire between Terminal G of the fuel gauge and ground. Are the resistances less than 5 ohms? If yes, go to step  8 If no, goto next step. See WIRING DIAGRAMS  .

  7. Check Instrument Cluster Ground

    Turn key OFF. Disconnect the 10-pin instrument cluster connector. Measure the resistance of the (Black/White) wire between Terminal No. 1J of the 10-pin instrument cluster connector and ground. Is the resistance less than 5 ohms? If yes, replace the instrument cluster printed circuit board. If no, service the (Black/White) wire. See WIRING DIAGRAMS  .
    8. NOTE: The fuel gauge system is equipped with a fuel anti-slosh/LFW module. Therefore, the instrument gauge tester must remain at the specified resistance for approximately 2 minutes to allow the fuel gauge to read the proper level.

  8. Check Fuel Sending Unit
    Turn key OFF. Disconnect the fuel pump assembly connector located under the vehicle between the fuel tank and the spare tire. Connect Rotunda Instrument Gauge System Tester (021-00055), or equivalent, between the (Blue/Red) wire at the fuel pump assembly connector and ground. Turn key ON. Adjust the instrument gauge system tester to the resistances shown in table: See FUEL GAGE RESISTANCE VALUES  table. Are the fuel gauge and low fuel warning lamp working properly? If yes, go to next step. If no, go to step  10 .
    FUEL GAGE RESISTANCE VALUES

    Fuel Gauge Resistance (ohms)
    F 160
    3/4 130
    1/2 95
    1/4 63
    E 23
    Low Fuel Warning Lamp On about 35

  9. Check Fuel Sending Unit Ground

    Turn key OFF. Disconnect the fuel pump assembly connector. Measure the resistance of the (Black) wire between the fuel pump assembly connector and ground. Is the resistance less than 5 ohms? If yes, replace the fuel sending unit. If no, service the (Black) wire. See WIRING DIAGRAMS  .

  10. Check Wire Between Fuel Anti-Slosh/Low Fuel Warning Module & Fuel Pump Assembly

    Turn key OFF. Remove the instrument cluster. Leave the instrument cluster connectors connected. Remove the fuel anti-slosh/LFW module from the instrument cluster. Disconnect the fuel pump assembly connector. Measure the resistance of the (Blue/Red) wire between Terminal No. 5 of the fuel anti-slosh/LFW module connector and the fuel pump assembly connector. Measure the resistance of the (Blue/Red) wire between Terminal No. 5 of the fuel anti-slosh/LFW module connector and ground. Is the resistance less than 5 ohms between the fuel anti-slosh/LFW module connector and the fuel pump assembly connector, and greater than 10,000 ohms between the fuel anti-slosh/LFW module connector and ground? If yes, go to step  12 . If no, go to next step. See WIRING DIAGRAMS  .

  11. Check Wire Between Instrument Cluster & Fuel Pump Assembly

    Turn key OFF. Disconnect the 10-pin instrument cluster connector. Disconnect the fuel pump assembly connector. Measure the resistance of the (Blue/Red) wire between Terminal No. 1E of the 10-pin instrument cluster connector and the fuel pump assembly connector. Measure the resistance of the (Blue/Red) wire between Terminal No. 1E of the 10-pin instrument cluster connector and ground. Is the resistance less than 5 ohms between the instrument cluster connector and the fuel pump assembly connector, and greater than 10,000 ohms between the instrument cluster connector and ground? If yes, replace the instrument cluster printed circuit board. If no, service the (Blue/Red) wire. See WIRING DIAGRAMS  .

  12. Check Circuit Between Fuel Anti-Slosh/Low Fuel Warning Module & Fuel Gauge

    Turn key OFF. Remove the instrument cluster. Leave the instrument cluster connectors connected. Measure the resistance of the circuit between Terminal No. 4 of the fuel anti-slosh/LFW module and Terminal B of the fuel gauge. Is the resistance less than 5 ohms? If yes, go to next step. If no, replace the instrument cluster printed circuit board.

  13. Check Fuel Gauge

    Turn key OFF. Disconnect the fuel pump assembly connector. Connect Rotunda Instrument Gauge System Tester (021-00055) or equivalent between the (Blue/Red) and (Black) wires at the fuel pump assembly harness connector. Remove the instrument cluster. Leave the instrument cluster connectors connected. Turn key ON. Measure the voltage between Terminal S of the fuel gauge (on the instrument cluster printed circuit board) and ground, at the resistances specified below. See FUEL GAUGE VOLTAGE/RESISTANCE VALUES  table. Do the voltage readings agree (approximately) with the chart? If yes, replace the fuel gauge. If no, replace the fuel indicator module. See WIRING DIAGRAMS  .
    FUEL GAUGE VOLTAGE/RESISTANCE VALUES

    Fuel Gauge Reading Resistance (ohms) Voltage (volts)
    F 160 5.55
    3/4 130 5.20
    1/2 95 4.62
    1/4 63 3.74
    E 23 2.14

  14. Check Low Fuel Warning Lamp System

    Turn key OFF. Remove the instrument cluster. Leave the instrument cluster connectors connected. Disconnect (remove) the fuel indicator module. Turn key ON. Ground Terminal No. 1 of the fuel indicator module connector. Does the low fuel warning lamp illuminate? If yes, replace the fuel indicator module. If no, go to next step.

  15. Check Power Supply To Low Fuel Warning Lamp

    Turn key OFF. Remove the instrument cluster. Leave the instrument cluster connectors connected. Turn key ON. Measure the voltage on the upper terminal of the low fuel warning light. Is the voltage greater than 10 volts? If yes, go to step  17 . If no, go to next step.

  16. Check Power Supply To Instrument Cluster

    Turn key OFF. Disconnect the 10-pin instrument cluster connector. Turn key ON. Measure the voltage on the (Gray/Blue) wire between Terminal No. 1D of the 10-pin instrument cluster connector and ground. Is the voltage greater than 10 volts? If yes, replace the instrument cluster printed circuit board. If no, service the (Gray/Blue) wire between the interior fuse panel and the instrument cluster. See WIRING DIAGRAMS  .

  17. Check Low Fuel Warning Lamp Bulb

    Turn key OFF. Remove the instrument cluster. Remove the low fuel warning light bulb. Measure the resistance between the terminals of the low fuel warning lamp bulb. Is the resistance approximately 16 ohms? If yes, replace the instrument cluster printed circuit board. If no, replace the low fuel warning lamp bulb.

  18. Check Fuel Anti-Slosh/Low Fuel Warning Module

    Turn key OFF. Remove the instrument cluster. Disconnect the fuel anti-slosh/LFW module. Disconnect the low fuel warning lamp. Measure the resistance between Terminal No. 1 of the fuel anti-slosh/LFW module connector and ground. Is the resistance less than 10,000 ohms? If yes, replace the instrument cluster printed circuit board. If no, replace the fuel anti-slosh/low fuel warning module.
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