B0520

Schematic:

CIRCUIT DESCRIPTION
The Instrument Panel Integration Module (IPM) monitors the air temperature in the rear duct via a 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 IPM controls the rear air mix door position in order to maintain the temperature selected on the rear temperature control.

CONDITIONS FOR RUNNING THE DTC
The ignition is turned ON.

CONDITIONS FOR SETTING THE DTC
The IPM detects the signal circuit is less than 0.09 V (5 counts) or greater than 4.88 V (250 counts).

ACTION TAKEN WHEN THE DTC SETS
A default value of 4.78 V (245 counts) in cold and 0.19 V (10 counts) in hot will be used by the IPM. The temperature displayed on the scan tool in the HVAC Sensors data list will be the default value. The actual sensor reading will be displayed on the scan tool in the Open/Short data list.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The DTC will become history if the IPM no longer detects a failure.
^ The history DTC will clear after 50 fault free ignition cycles.
^ The DTC can be cleared with a scan tool.

TEST DESCRIPTION

Steps 1-12:

The number(s) below refer to the step number(s) 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.