The Heating, Ventilation and Air Conditioning (HVAC) system is divided into
2 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 control system. The second, HVAC Systems - Automatic,
has all the procedures specific to the automatic control system.
For systems with DTCs, begin the system diagnosis with the Diagnostic System
Check. Refer to
Diagnostic System Check - Vehicle
in Vehicle DTC Information.
The Diagnostic System Check will provide the following information:
| • | The identification of the control modules which command the system. |
| • | The ability of the control modules to communicate through the Class 2
serial data circuit. |
The use of the Diagnostic System Check will 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. The HVAC Description and Operation information
is divided into:
The Air Delivery Description and Operation contains the following topics:
| • | HVAC control components |
| • | Recirculation operation |
The Air Temperature Description and Operation contains the following topics:
| • | HVAC control components |
| • | Heating and A/C operation |
