Regal V6-3.8L VIN K (1997)
Control Module HVAC: Customer Interest
A/C - Temperature Difference Side to Side/DTC's Set
File In Section: 01 - HVAC
Bulletin No.: 02-01-39-001
Date: February, 2002
TECHNICAL
Subject:
HVAC Temperature Difference Side to Side and/or DTC B0361, B0441 Set (Replace HVAC Controller, Splice into Backlighting Circuit)
Models:
1997-99 Buick Century, Regal
1998-99 Oldsmobile Intrigue
with RPO CJ2
Condition
Some customers may comment on a temperature variation between the left and right hand ducts. Typical concerns may include that the right side of the
vehicle cools down but the left stays warm or the opposite. This condition is sometimes associated by the customer with a recent service visit for other
non-related repairs. The codes, DTC 80361 or B0441, may be present but will not illuminate a telltale lamp.
Cause
The HVAC controller unit and the TEMP door actuator motors rely on a feedback system that supplies the controller with count values in order to
accurately adjust the air temperature. When battery power is interrupted to the HVAC controller, the current actuator position values are lost. When
power is restored, the controller will perform a "sweep test" of the doors from full cold to full hot and record the end values for reference. Over time, the
TEMP doors may develop some flexing when run to their extremes. This flexing allows the count values to run out of range (beyond 0-255) and results
in DTC code 80361 or 80441 to set.
Correction
A revised HVAC controller has been released with new programming that allows for a wider tolerance in the expected range of the TEMP door. Replace
the controller using the procedure below:
Important:
On the 1997 Buick Century and Regal, additional steps are required. You will have to run a jumper wire to the new HVAC controller. Be sure to
follow the additional 1997 model year steps below.
1.
Disconnect the negative battery cable.
Important:
On the Buick Regal, the console must first be removed to access the HVAC controller For Buick Century and Oldsmobile Intrigue, skip to Step 10.
2.
Apply the parking brake and block wheels.
3.
Shift the transmission to first gear.
4.
Remove the console trim plate and disconnect the electrical harness.
5.
Disconnect the cigarette lighter sockets.
6.
Remove the console storage box.
7.
Remove the console control plate and disconnect electrical harness for traction control and heated seats, if equipped.
8.
Remove the console retaining bolts.
9.
Remove the console from the vehicle.
10.
Remove the HVAC trim panel, if equipped.
11.
Remove the HVAC controller retaining bolts.
