Initial Inspection and Diagnostic Overview

System Diagnostics
* Fault detection is through active and stored Diagnostic Trouble Codes (DTC's)
* DTC's are displayed by the DRB III.
* Active DTC's are those which currently exist in the system.
* The condition causing the fault must be repaired in order to clear this type of DTC.
* Stored DTC's are those which occurred in the system since the A/C-Heater Control Module received the last "clear diagnostic info" message.

System Controls
The A/C-Heater Control Module:
* is fully addressable with the DRB III.
* communicates over the Programmable Communication Interface Multiplex System (PCI) Bus. Refer to Body Control System. Body Control Module