Low Fuel Warning

CAUTION: The following actions or conditions will cause damage to and require replacement of the electronic fuel gauge.
^ Applying battery voltage to the low fuel warning lamp to test bulb operation. The lamp should be checked with an ohmmeter to verify continuity.
^ An open in the warning lamp tier ground circuit.
^ Inadvertent installation of a low fuel warning module that is not required on vehicles equipped with the electronic cluster.

Verification of proper failure mode is important before undertaking any diagnostic procedures. Listed are typical failure modes and the recommended diagnostic procedures.
1. Low fuel warning lamp does not illuminate during prove out.
a. Check for a good ground at the warning lamp bulb.
b. Check warning lamp bulb.
c. Check wiring harness between fuel gauge and low fuel warning lamp for open circuit.
d. Connect a test lamp between the low fuel warning terminal of the fuel gauge and ground during prove out. Test lamp should glow for two to four seconds when the ignition switch is turned ON. If lamp does not glow, Service and Repair
e. Check the instrument panel ground for a tight connection.
2. Low fuel warning lamp is always ON, with the fuel level indicator five segments or above.
a. Check wiring harness between fuel gauge and the low fuel warning lamp for short.
b. Service and Repair
3. Low fuel warning lamp does not illuminate with fuel gauge indication of four segments or less.
a. If prove out does not occur, follow diagnostic procedure in step 1.
b. If prove out occurs, Service and Repair
4. Fuel gauge ISO symbol flashes continually regardless of fuel level indication.
a. Check fuel sender ground for a tight connection.
b. Fuel Sending Unit
c. Check instrument cluster ground for a tight connection.
5. Fuel gauge ISO symbol does not flash with fuel level indications of four segments.
a. Check fuel sender ground for a tight connection.
b. Fuel Sending Unit
c. Check instrument cluster ground for a tight connection.