PCM - Heater Blows Cold Air From Vents

9234chrysler02

NO.: 24-07-92

GROUP: Heater & A/C

DATE: Jul. 13, 1992


SUBJECT:
Heater Blowing Cold Air


THIS BULLETIN APPLIES TO AUTOMATIC TEMPERATURE CONTROL (ATC)

EQUIPPED VEHICLES.


MODELS:

1991 1/4 -1992 (BB) Monaco/Premier

1991 VEHICLES BUILT AFTER OCTOBER 8,1990 (MDH 10-08-xx) ARE DESIGNATED 1991 1/4. THESE VEHICLES CAN BE IDENTIFIED BY AN 8 IN THE TWELFTH POSITION OF THE VIN.


SYMPTOM/CONDITION:

In low ambient temperatures the blower delay feature may not engage and cold air may blow from the climate control vents if either the HEAT or HEAT/DEFROST modes were selected. This condition is caused by the blower fan coming on when the coolant temperature is about 20 degrees F (-7 degrees C). Customer complaints of this condition can be resolved by installing a new Powertrain Control Module (Single Board Engine Controller). When ambient temperatures are below 70 degrees F (21 degrees C), this new module will delay turning the fan on in these modes until the coolant temperature reaches 120 degrees F (49 degrees C).


PARTS REQUIRED:

1 Powertrain Control Module (Single Board Engine Controller) 4728139
1 Authorized Modification Label 4275086


REPAIR PROCEDURE:

This bulletin involves replacing the Powertrain Control Module (SBEC) with a revised module.

1. Replace the Powertrain Control Module (SBEC) with PN 4728139, as outlined in the Ignition System section (Group 8D) of the appropriate service manual.





2. Type the required information on the Authorized Modification Label, as illustrated, and attach near the VECI label.


POLICY:
Reimbursable within the provisions of the warranty.


TIME ALLOWANCE:
Labor Operation No. 08-19-91-96............................0.4 Hrs.


FAILURE CODE:
AM - Authorized Modification