B1020

CIRCUIT DESCRIPTION
This DTC is an indication of a malfunction with the Infrared thermistor which is internal to the rear auxiliary control module.

CONDITIONS FOR RUNNING THE DTC
The ignition is turned ON.

CONDITIONS FOR SETTING THE DTC
^ This test checks the value of the Infrared thermistor (part of the Rear Aux ECC module) and the stored thermistor values. If the stored values are above or below the system specifications, the DTC will be set.
^ The above conditions are present for 3 consecutive failures.

ACTION TAKEN WHEN THE DTC SETS
^ The automatic portion of the heater and A/C system will be disabled.
^ A calibrated (failsoft) value of 75 degrees will be used in all HVAC calculations requiring the temperature of the rear passenger compartment.

CONDITIONS FOR CLEARING THE DTC
^ The DTC will become history if the HVAC Module 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

Steps 1-6: