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Test B: Fuel Gauge Inaccurate Or 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  under SELF-DIAGNOSTIC SYSTEM.
  2. Access and disconnect Black 7-pin in-line harness connector C420. In-line harness connector C420 is located below right rear of vehicle, near wheel well. Connect Signal Generator and Instrument Panel Tester (J33431-C) between in-line harness connector terminals C420 (female side) "A" (Purple wire) and "C" (Black wire). See Figure . Turn ignition switch to RUN position. Vary resistance on Signal Generator and Instrument Panel Tester (J33431-C from 40-250 ohms. Use fuel level conversion table to convert resistance to fuel gauge actual display. See FUEL LEVEL SPECIFICATIONS  table. If fuel gauge does not display correct fuel level, go to next step. If fuel gauge displays correct fuel level, go to step  4 .
  3. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). DLC is located below left side of instrument panel, near steering column. Vary resistance on Signal Generator and Instrument Panel Tester (J33431-C from 40-250 ohms. Turn ignition switch to RUN position. Using scan tool, observe fuel level sensor parameter in Powertrain Control Module (PCM) EVAP data list. Use fuel level conversion table to convert resistance to fuel gauge actual display. See FUEL LEVEL SPECIFICATIONS  table. If scan tool does not display correct fuel level voltage, go to step  5 . If scan tool displays correct fuel level voltage, go to step  11 .
  4. Inspect in-line harness connector C420 for poor connections. Inspect Purple wire for high resistance between in-line harness connector C420 terminal "A" and fuel level sensor. Inspect Black wire for high resistance between in-line harness connector C420 terminal "C" and fuel level sensor. Inspect for misaligned fuel level sensor or deformed fuel tank. If any problem does not exist, go to step  7 . If any problem exists, repair in-line harness connector, Purple wire, Black wire, fuel level sensor or fuel tank as necessary. After repair, go to step  13 .
  5. Inspect Purple wire for high resistance between PCM harness connector C2 terminal No. 72 and in-line harness connector C420 terminal "A". If problem does not exist, go to next step. If problem exists, repair Purple wire as necessary. After repair, go to step  13 .
  6. Inspect Black wire for high resistance between PCM connector C2 terminal No. 13 and in-line harness connector C420 terminal "D". If problem does not exist, go to step  9 . If problem exists, repair Black wire as necessary. After repair, go to step  13 .
  7. Remove fuel level sensor. Check for stuck fuel level sender or foreign material in gas tank. If problem does not exist, go to next step. If problem exists, repair fuel level sensor as necessary. After repair, go to step  13 .
  8. Using DVOM, measure resistance between fuel level sensor terminals while moving float arm. Compare DVOM readings to fuel level sender specifications. See FUEL LEVEL SPECIFICATIONS  table. If resistance change is not smooth across specified range, go to step  10 . If resistance change is smooth across specified range, see DIAGNOSTIC AIDS  .
  9. Inspect PCM harness connector for poor connections. If problem does not exist, go to step  12 . If problem exists, repair PCM harness connector as necessary. After repair, go to step  13 .
  10. Replace fuel level sensor. After repair, go to step  13 .
  11. Replace Instrument Panel Cluster (IPC). After repair, go to step  13 .
  12. Replace PCM. Program PCM. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After repair, go to next step.
  13. Using scan tool, clear DTCs. Operate system to verify repair. If system is not operating correctly, repeat test beginning at step  2 .
FUEL LEVEL SPECIFICATIONS

Fuel Gauge Display Resistance (Ohms) Fuel Level Sensor Voltage Fuel Remaining (Gallons)
E 40-80 0.73-1.24 0-2
1/4 130 1.75 6
1/2 169 2.04 10
3/4 210 2.29 14
F 241-250 2.48-2.51 17-18
Low Fuel Indicator On 94 1.39 3
Low Fuel Indicator Off 103 1.49 4
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