Test B: Fuel Gauge Inaccurate
- Turn ignition switch to LOCK position. Disconnect fuel pump module 6-pin harness connector C343. Fuel pump module is located in fuel tank. Connect Rotunda Instrument Gauge Tester (014-R1063) test leads to ground and fuel pump module harness connector C343 terminal No. 5 (Blue/Red wire). Set tester to 160 ohms. Turn ignition switch to RUN position. Turn tester on and wait one minute. Fuel gauge should read full or above. Turn ignition switch to LOCK position. Set tester to 15 ohms. Turn ignition switch to RUN position and wait one minute. Fuel gauge should read empty or below. If fuel gauge is as specified, go to next step. If fuel gauge is not as specified, go to step 4.
- Visually inspect fuel tank for damage or deformation. If fuel tank is okay, go to next step. If fuel tank is not okay, replace fuel tank as necessary. Retest system.
- Visually inspect fuel pump module for damage or connector problems. Inspect float and float rod assembly for damage or float rod obstruction. If fuel pump module and wiring is okay, replace fuel sending unit. Retest system. If fuel pump module and wiring is damaged, repair as necessary.
- Turn ignition switch to LOCK position. Measure resistance between ground and fuel pump module harness connector terminal No. 6 (Black wire). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black wire between fuel pump module and ground point. Ground point is located in left rear of vehicle near liftgate.
- Disconnect instrument cluster 12-pin harness connector C266a. Measure resistance of Blue/Red wire between fuel pump module harness connector terminal No. 5 and instrument cluster harness connector C266a terminal No. 10. See Fig 1. Measure resistance between ground and instrument cluster harness connector C266a terminal No. 10 (Blue/Red wire). Resistance should be less than 5 ohms between instrument cluster and fuel pump module, and 10 k/ohms or more between instrument cluster and ground. If resistance is as specified, go to next step. If resistance is not as specified, repair open or short to ground in Blue/Red wire.
- Disconnect all instrument cluster harness connectors. Inspect for corroded or pushed out pins. Connect all instrument cluster harness connectors. Operate system and verify if concern still exists. If concern still exists, replace instrument cluster. See REMOVAL & INSTALLATION . If concern does not exist, system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.
Courtesy of FORD MOTOR CO.