HVAC System Diagnosis
CIRCUIT DESCRIPTIONThe HVAC control module communicates with the rear HVAC control module through the driver HVAC control assembly signal and driver HVAC control assembly clock signal circuits. This communication link is only used by the HVAC control module and the rear HVAC control module to exchange HVAC data.
CONDITIONS FOR RUNNING THE DTC
The ignition is turned ON.
CONDITIONS FOR SETTING THE DTC
There is a loss of communications between the HVAC control module and the rear HVAC control module.
ACTION TAKEN WHEN THE DTC SETS
The rear HVAC control module will lose all automatic control. The rear blower motor can be controlled manually by the blower switch on the rear HVAC control module.
CONDITIONS FOR CLEARING THE DTC
^ The DTC will become history if the HVAC control 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
