I have a 2001 Mercury Grand Marquis. The miles per gallon indicator is not operating properly. Must assume there is a sensor that sends the information to the display. If so, where is it located and can it be replaced easily?
Vehicle is equipped with a self-diagnostic system and I would suggest starting with it. The fuel remaining is linked to the odometer and fuel sending circuit.
NOTE: Enter self-diagnostic mode to determine if a problem exists in sending unit circuits or display.
1. Turn ignition switch to LOCK position. Simultaneously press and hold E/M and SELECT buttons on message center. While holding buttons, turn ignition switch to RUN position. If instrument cluster flashes on and off continuously, replace instrument cluster. If instrument cluster displays upper 2 and lower 2 bars or just bottom bar is displayed in temperature gauge, diagnose temperature gauge system. If instrument cluster displays upper 2 and lower 2 bars in fuel gauge, diagnose fuel gauge system.
2. CO (circuit open) or CS (circuit short) will be displayed if FUEL REMAINING or DISTANCE TO EMPTY is selected on message center and an open or short exists in fuel tank sending unit circuitry. If ERROR is displayed in odometer display, diagnose speedometer/odometer circuitry.
3. If problem remains, connect New Generation Star (NGS) or Worldwide Diagnostic System (WDS) tester to Data Link Connector (DLC). Perform data link diagnostics test. If NGS/WDS tester responds with CKT914, CKT915 or CKT70=ALL ECUS NO RESP/NOT EQUIP, repair module communications problem.