For 1990-2009 cars

The Heating, Ventilation and Air Conditioning (HVAC) system is divided into three sections. The first, Heating, Ventilation and Air Conditioning, has all procedures that pertain to a HVAC component or function that are not specifically associated with an automatic or manual control system. The second, HVAC Systems-Manual, has all procedures specific to the manual control system. The third, HVAC Systems-Automatic, has all the procedures specific to the automatic control system.

For systems without DTCs, refer to Symptoms - HVAC Systems - Manual in order to identify the correct procedure for diagnosing the system and where the procedure is located.

For systems with DTCs, refer to Diagnostic System Check - HVAC Systems - Automatic in order to identify and lead the technician to the correct diagnostic procedure.

Review the Description and Operation information to help you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the Description and Operation information will also help you determine if the condition described by the customer is normal operation. Refer to Air Delivery Description and Operation .