Fuel Gauge: Testing and Inspection

1. Disconnect the fuel gauge sending unit.
2. Turn the ignition switch to the ON position. The fuel gauge should be at its lowest position. Turn the ignition switch OFF.
3. Ground fuel gauge sending unit connector Pin 3. Turn ignition switch to the ON position. The fuel gauge should be at its highest position. Turn ignition switch OFF then ON, after a sending unit signal change to disable the cluster electronic gauge dampening mechanism.
a. If OK, check the fuel gauge sending unit connector for proper connection. If the connections are OK, Check for Fuel Level Sensor Diagnosis.
b. If not OK, connect the sending unit. Remove the cluster and check for an open or short in the sending unit wiring. The sending unit will be less than 1080 ohms and greater than 50 ohms depending upon fuel level. If the sending unit wiring is open or a short circuit, repair as necessary.
c. If the sending unit wiring is OK, replace the gauge assembly. If the condition persists, replace the cluster printed circuit board.

Cluster Wire Harness Connector:

Powertrain Control Module Pin Location:

Fuel Gauge Incorrectly Indicates Empty
The fuel system uses both the instrument cluster and the Powertrain Control Module (PCM) to monitor the fuel level sending unit. If the PCM fuel monitoring circuits senses an open circuit, the increased circuit resistance will causes a false fuel gauge empty reading. Check for continuity between cluster wire harness connector Pin J2-10 and Pin 23 of the PCM. If there is no continuity, repair as necessary. If there is continuity, refer to Fuel Gauge test.

Low Fuel Warning Circuit (Tachometer Cluster Only)
The low fuel warning lamp receives its signal from the fuel gauge drive circuit. Due to production variations, the point where the lamp illuminates, may vary from 1/16 to 3/16 mark on the fuel gauge. There is a built in time delay before the lamp illuminates. This prevents the lamp from going on and off under various road conditions.
1. Verify that the fuel gauge is operating properly
2. Check the low fuel warning lamp assembly.
3. If the lamp still does not function under a low fuel condition replace the printed circuit board.