Liberty 4WD V6-3.7L VIN K (2003)
Control Module HVAC: All Technical Service Bulletins
A/C - Won't Cool/Heat Properly
NUMBER: 24-009-03
GROUP: Heating & Air Conditioning
DATE:December 05, 2003
SUBJECT:
Unable To Obtain Temperature - A/C Heater Control Head Calibration Procedure
MODELS:
2003 - 2004
(KJ)
Liberty/Cherokee (All Markets)
NOTE:
This bulletin applies to vehicles built between November 20, 2002 (MDH 1120XX) and February 01, 2004 (0201XX).
DISCUSSION:
A manual calibration procedure for the a/c heater temperature control is available. This quick procedure may be of assistance to ensure that the a/c heater
control head is correctly calibrated to the electric blend air door actuator. If calibration between the two components is not correct, then the customer
may experience conditions where the a/c heater system may not obtain full cooling or full heating capabilities. If the blend air door actuator does not
seem to be functioning properly, or the air seems to be too warm when the temperature select knob is in the full cold position, or the air seems too cool
when the temperature select knob is in the full hot position, then a manual calibration of the a/c heater control head can be performed.
The software capability that allows for manual calibration of the a/c heater temperature control is only available on vehicles built approximately between
November 20, 2002 and February 01, 2004. The following temperature control heads, with their respective part numbers, have the software that allows
for manual calibration.
NOTE:
The manual calibration procedure can only be started within the first ten (10) seconds after the ignition switch has been turned from the OFF to the
ON position. Make certain that the battery is fully charged prior to performing the manual calibration procedure.
NOTE:
The pause made at each end of the knob rotation (sweep) is important. If the pause is too short (less than 0.5 seconds), or if the pause is too long
(greater than 1.5 seconds), the manual calibration may not occur correctly.
MANUAL CALIBRATION PROCEDURE:
1.
With the ignition switch in the OFF position, move the temperature select control knob to its middle (12 o'clock) position.
2.
Turn the ignition switch to the ON position (do not start the vehicle engine).
