Number: |
90-101-1A
|
Section: |
1A
|
Corporate Bulletin No.: 931107
Subject: |
LOSS OF HEATING OR COOLING CONTROL
|
Model and Year: |
1990 Y CAR WITH ELECTRONIC AIR CONDITIONING (C68) OPTION |
TO: |
ALL CHEVROLET DEALERS
|
CONDITION: |
The temperature of air coming from the HVAC system cannot be changed. A code 01 or 02 may also be set in the HVAC control head.
|
A secondary condition of false trouble codes being set in the ECM or CCM may also be present.
CAUSE: |
The air mix door of the Heater and A/C system will not move out of
the full hot or full cold position causing loss of heating or cooling
control. If the courtesy or radio fuse, which supplies power to the A/C
control system, is installed with the ignition key in the ON position,
the automatic A/C control system may lose its calibration.
|
Removal or installation of any fuse should always be done with the ignition key in the OFF position!
CORRECTION: |
Use the following procedure to re-calibrate the system:
1) |
Make sure the courtesy and radio fuses are installed in the fuse block.
|
2) |
Disconnect the negative battery cable for 1 minute and then
reconnect it. The A/C system will go through a 2 minute calibration
sequence, which keeps the blower fan off, when the battery power is
restored. |
|
(If a DELCO-LOC II security code has been programmed originally into the
radio by the customer, the radio may display "LOC" when the battery
cable is disconnected. If this condition occurs, the customer will have
to re-enter his/her security code to turn on the radio. Refer to Section
9A in the service manual for further information on this procedure.)
3) |
Verify the proper operation of the HVAC system.
|
Other causes such as wiring disconnects, air mix door motor
condition, Freon loss, etc. may create these same conditions. If the
above procedure does not correct the vehicle, refer to the 1990 Corvette
Service Manual for additional diagnostics.
NOTICE: |
WHILE WORKING ON THE HVAC SYSTEM, DO NOT RUN THE AIR MIX DOOR MOTOR
WHEN IT IS REMOVED FROM THE HEATER CASE. THIS WILL DAMAGE THE MOTOR.
|
Labor Operation Number: |
T1456
|
Labor Time: |
0.2 Hours |
This is prolly not your problem, but it appears to be the only TSB that even comes close...and it's info for others, just in case someone IS experiencing these symptoms. I'll keep lookin...
|UPDATED|12/17/2012 10:51:18 AM (AZT)|/UPDATED|
______________
Joel Adams
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"