B1311

CIRCUIT DESCRIPTION
The HVAC control processor monitors the ambient air temperature via a ambient air temperature sensor. When the air is cold, the sensor resistance and signal voltage are high. When the air is warm, the sensor resistance and signal voltage are low. The HVAC control processor displays the ambient air temperature.

CONDITIONS FOR RUNNING THE DTC
The ignition is turned ON.

CONDITIONS FOR SETTING THE DTC
The HVAC control processor detects the signal circuit is less than 5 counts (0.09 V).

ACTION TAKEN WHEN THE DTC SETS
^ The HVAC control processor will store the trouble code in memory.
^ A default value will be used for the sensor data by the HVAC control processor to allow the A/C system to operate.

CONDITIONS FOR CLEARING THE DTC
^ The DTC will become history if the HVAC control processor no longer detects a failure.
^ The history DTC will clear after 100 fault-free ignition cycles.
^ The DTC can be cleared with a scan tool.

DIAGNOSTIC AIDS
If the condition is not present, refer to Testing for Intermittent and Poor Connections in Diagrams.

TEST DESCRIPTION

Steps 1-12:

The numbers below refer to the step numbers on the diagnostic table.
3. Tests for the proper operation of the circuit in the high voltage range.
4. Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.