A/C - Air From Defrost Vents In Vent Mode

Group Ref.: HVAC

Bulletin No.: 431204A

Date: April, 1994

SUBJECT:
A/C AIR FROM DEFROST VENTS IN VENT MODE
(REPLACE A/C CONTROL HEAD)

MODEL:
1994 BUICK ROADMASTER
WITH RPO C68

THIS BULLETIN IS BEING REVISED TO CORRECT WARRANTY INFORMATION - LABOR OPERATION NUMBER. PLEASE DISCARD BULLETIN 431204.

CONDITION:

A customer may describe this condition as being in "defrost" mode although the A/C control head displays that it is in the "vent" mode. This condition happens when exiting from the "defrost" mode if the previous mode was "auto vent".

CAUSE:

While in the "defrost" mode, if the "defrost" button is pressed again. the system was designed to return to the previous mode. However. if the previous mode was "auto-vent" the system will return to the "auto" (compressor on) and the display on the control head will show "auto-vent". This is due to a software condition inside the control head.

CORRECTION:

To correct, replace the A/C control head with a new head, P/N 16199483, following procedures in the Service Manual, Section 10.

PART AVAILABILITY:

Parts are currently available from GMSPO.

WARRANTY INFORMATION:

For vehicles repaired under warranty, use:

Labor Operation: D0362

Use Published Labor Operation Time.