HVAC Actuator Recalibration Will Not Complete The Calibration - keywords B0228 B0413 B0423 B3779 calibrate CJ3 cold control door head hot HVAC inoperative mode relearn temp temperature

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

When replacing the Front HVAC control head or an HVAC actuator it will be necessary to allow the HVAC control head to perform a calibration procedure. It has been found that when performing the "Actuator Recalibration" procedure on vehicles with either CJ3 or C67 Manual Hvac, the "Scan Tool" (Tech 2) method does not work properly. When performing the procedure with the Tech 2 it will NOT give any indication that it is not working properly.

At this time do not use the "Scan Tool" (Tech 2) method, use the "Alternate Method" (w/o Scan Tool) listed below.

Alternate Method (w/o Scan Tool)

1. Clear all DTCs AND REMOVE THE SCAN TOOL.
2. Place the ignition switch to the OFF position.
3. Remove the HVAC/BATT fuse for a minimum of 10 seconds.
4. Install the HVAC/BATT fuse.
5. Start the vehicle.
6. Wait 40 seconds for the HVAC control head to self-calibrate.
7. Verify that no DTCs have set.

Important: Do not adjust any controls on the HVAC control head while the HVAC control head is self-calibrating. If interrupted, improper HVAC performance will result.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.