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Test D: Fuel Gauge Inaccurate

  1. Turn ignition switch to LOCK position. Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition switch to RUN position. Using NGS tester, retrieve and record continuous instrument cluster and Rear Electronic Module (REM) DTCs. Clear instrument cluster and REM DTCs. Using NGS tester, perform instrument cluster and REM self-test. If REM DTC B1201 and instrument cluster DTC U1131 are not retrieved, go to next step. If REM DTC B1201 and/or instrument cluster DTC U1131 are retrieved, go to step  6 .
  2. Using NGS tester, select instrument cluster active command FUEL LEVEL CONTROL. Trigger FUELLEVEL. Scroll FUEL LEVEL to 0 percent, 50 percent, then 100 percent while observing fuel gauge. Fuel gauge should display empty at 0 percent, half at 50 percent and full at 100 percent. If fuel gauge operates as described, go to next step. If fuel gauge does not operate as described, replace instrument cluster.
  3. Turn ignition switch to LOCK position. Disconnect Fuel Delivery Module (FDM) harness connector. Measure resistance between terminals No. 2 and 3 at FDM (component side). See Fig 1 . Resistance should be 14-18 ohms when fuel tank is empty and 151-159 ohms when fuel tank is full. If resistance is as specified, go to next step. If resistance is not as specified, replace FDM.
    4. NOTE: It may be necessary to lower fuel tank to access Jet Pump Module (JPM) harness connector.
  4. Disconnect Jet Pump Module (JPM) harness connector. Measure resistance between terminals No. 2 and 3 at JPM (component side). See Fig 1 . Resistance should be 17-21 ohms when fuel tank is empty and 156-164 ohms when fuel tank is full. If resistance is as specified, go to next step. If resistance is not as specified, replace JPM.
  5. Visually inspect fuel tank. If fuel tank is okay, inspect float and float rod for damage, and repair or replace components as necessary. If fuel tank is damaged, repair or replace fuel tank as necessary.
  6. Turn ignition switch to LOCK position. Disconnect Rear Electronic Module (REM) harness connectors C420c and C420d. Measure resistance between ground and terminals No. 15 (White/Red wire) and No. 16 (White/Blue wire) at REM harness connector C420d. See Figure . Measure resistance between ground and terminal No. 23 (Brown wire) at REM harness connector C420c. If any resistance is 10 k/ohms or less, go to next step. If all resistances are greater than 10 k/ohms, go to step  8 .
    7. NOTE: It may be necessary to lower fuel tank to access Jet Pump Module (JPM) harness connector.
  7. Disconnect Fuel Delivery Module (FDM) harness connector. Disconnect Jet Pump Module (JPM) harness connector. Measure resistance between ground and terminals No. 15 (White/Red wire) and No. 16 (White/Blue wire) at REM harness connector C420d. Measure resistance between ground and terminal No. 23 (Brown wire) at REM harness connector C420c. If any resistance is 10 k/ohms or less, repair short to ground in appropriate circuit between REM and FDM, or between REM and JPM. If all resistances are greater than 10 k/ohms, replace FDM and/or JPM as necessary.
  8. Disconnect Fuel Delivery Module (FDM) harness connector. Disconnect Jet Pump Module (JPM) harness connector. Measure resistance in White/Red wire between terminal No. 15 at REM harness connector C420d and terminal No. 2 at FDM harness connector. See Figure and Fig 2 . Measure resistance in White/Blue wire between terminal No. 16 at REM harness connector C420d and terminal No. 2 at JPM harness connector. Measure resistance between terminal No. 23 (Brown wire) at REM harness connector C420c and terminal No. 3 (Brown/Blue wire) at JPM harness connector. Measure resistance between terminal No. 23 (Brown wire) at REM harness connector C420c and terminal No. 3 (Brown/Red wire) at FDM harness connector. If all resistances are 5 ohms or less, go to next step. If any resistance is greater than 5 ohms, repair open in appropriate wire.
  9. Turn ignition switch to RUN position. Measure voltage at terminals No. 15 (White/Red wire) and No. 16 (White/Blue wire) at REM harness connector C420d. Measure voltage at terminal No. 23 (Brown wire) at REM harness connector C420c. If voltage does not exist at any terminal, go to next step. If voltage exists at any terminal, repair short to voltage in appropriate wire between REM and FDM, or between REM and JPM.
  10. Measure voltage at terminals No. 2 (White/Red wire) and No. 3 (Brown/Red wire) at FDM harness connector. Measure voltage at terminals No. 2 (White/Blue wire) and No. 3 (Brown/Blue wire) at JPM harness connector. If voltage does not exist at any terminal, replace FDM and/or JPM as necessary. If voltage exists at any terminal, repair short to voltage in appropriate wire between REM and FDM, or between REM and JPM.
Fig 1: Identifying Fuel Delivery Module & Jet Pump Module Terminals (Component Side)
G00011089Courtesy of FORD MOTOR CO.
Fig 2: Identifying Fuel Delivery Module & Jet Pump Module Harness Connector Terminals
G00011090Courtesy of FORD MOTOR CO.
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