DTC 168

CIRCUIT DESCRIPTION
The fuel level sensor in the fuel tank is a variable resistor. As the fuel level changes, the resistance of the fuel sensor changes. The Instrument Panel Cluster (IPC) monitors changes in the voltage caused by the changes in the resistance of the sensor to determine fuel level.

CONDITIONS FOR SETTING THE DTC
The fuel gauge circuit is tested every 100 ms. DTC 168 will set in the following ways:
^ When the circuit is open.
^ Shorted to battery.
^ The resistance of the fuel sensor is out of range (more than 350 ohms) for more than 8 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ Stores a DTC 168 in memory.
^ The fuel gage will return to the zero position.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The resistance must be greater than 350 ohms for 4 seconds to clear the fault in the next monitoring cycle.
^ Conditions for the fault are no longer present.
^ Using a scan tool.

DIAGNOSTIC AIDS
Use the Freeze Frame and/or Failure Records data in order to locate an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data may aid in determining the number of miles since the DTC set. The Fail Counter and Pass Counter can also aid in determining the number of ignition cycles that the diagnostic reported a pass and/or fail. Operate the vehicle within the same freeze frame conditions RPM, engine load, vehicle speed, temperature, etc.). This will isolate when the DTC failed. Refer to Testing for Intermittent and Poor Connections in Diagrams.

TEST DESCRIPTION

Steps 1-8:

The number(s) below refer to the step number(s) on the diagnostic table.
2. This test determines whether there is a short to voltage or the open in the fuel level signal circuit or if there is an internal IPC problem.
3. This test determines whether the short to voltage or the open is in the fuel level signal circuit or if there is an internal fuel sender problem.
4. This test determines whether the short to voltage or the open is in the fuel level signal circuit or if there is an internal ECM problem.
8. Clear all DTCs within the IPC after performing this diagnostic table.