B3584

CIRCUIT DESCRIPTION
The HVAC Control Module - Rear Auxiliary monitors the air temperature in the rear heater 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 Rear HVAC control module controls the air mix door position in order to maintain the temperature selected on the temperature control.

CONDITIONS FOR RUNNING THE DTC
The ignition is turned ON.

CONDITIONS FOR SETTING THE DTC
The HVAC Control Module - Rear Auxiliary detects the signal circuit is less than 0.09 V (5 counts) or greater than 4.90 V (250 counts).

ACTION TAKEN WHEN THE DTC SETS
This test checks the Output temperature sensor value stored in the HVAC Auxiliary (ECC) controller. If the value stored is above the output max temperature value or below the minimum output temperature value, the DTC shall set. If the code is currently set, the actual sensor reading shall be displayed on the scan tool.

CONDITIONS FOR CLEARING THE DTC
- The DTC will become history if the HVAC Control Module - Rear Auxiliary 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 1-3:

Steps 4-12:

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