A/C - New Control Unit

File In Section: 1 - HVAC

Bulletin No.: 71-11-04

Date: May, 1997

INFORMATION

Subject:
New Heater and A/C Control Unit

Models:
1997 Catera

A new Heater and A/C Control unit was introduced into Catera production starting at sequence number VR138045. This new panel features more extensive self diagnostic capabilities including more diagnostic codes, parameter data and tests for the HVAC system.

This new Heater and A/C Control unit is now the only replacement part available from GMSPO and can be used on any 1997 Catera. However, replacement control units must be programmed using the Tech 2 in order to operate properly. This is true regardless of VIN sequence number. If the replacement control is not programmed, the rear defogger may not operate and/or other functions of the panel may be inoperative and a code F52 may be stored.

After installation of a service Heater and A/C Control, program the unit using the Tech 2. The programming option is initiated by selecting "F4: Programming" on the "Heater and Air Conditioning" menu. At this point the Tech 2 currently asks a question regarding "U.S. or Canadian car?" and the question "Does the car have side airbags?" To program the Heater and A/C Control answer the "Airbag" question "NO" for 1997 VIN's prior to VR138045 and "YES" for VIN's VR138045 and after. Disregard whether the car actually has side airbags or not and answer the airbag question based on sequence number according to the above.

In future CD-ROM updates the Heater and A/C Control programming question on the Tech 2 will change from "Does the car have side airbags?" to something regarding the VIN or other type of information. When this occurs, answer the particular question(s) asked. Until this time, program the Heater and A/C Control by answering the airbag question according to the above instructions.