Download 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.