Sunday, September 30, 2012


How to perform A/C-HEATER CONTROL CALIBRATION procedure

The Vehicle is 2006 Chrysler Town & Country.

The Calibration procedure helps many a times during No heat problems.
The heater blows no heat but only cold air.
In such cases the problem is due to faulty Actuator motor or problem with A/C heater control module.
But even after replacing these faulty or weak parts the problem remains the same.
On such cases performing the A/C heater control calibration helps.

The procedure is as follows :----

The A/C-heater control module must be re-calibrated each time an actuator motor or the A/C-heater control is replaced. 
If the vehicle is so equipped, the calibration procedure also includes rear HVAC positions for each actuator motor.

The details are as follows:----

First of all turn the ignition switch to the On position.

There are two types of temperature control systems on vehicle.Manual temperature control system or Automatic temperature control system.

For  manual temperature control (MTC) system, 
  • Press and hold the Rear Wipe/Wash and Re-circulation buttons for at least five seconds. 
The MTC A/C-heater control Rear Wipe/Wash button light emitting diode (LED) and Recirculation button LED, will begin to flash when the calibration procedure has begun.

And with the automatic temperature control (ATC) system, 
  • Simultaneously press and hold the Power and Recirculation buttons on the A/C-heater control for at least five seconds. 
The ATC A/C-heater control Delay and Recirculation graphics will begin to flash when the calibration procedure has begun.

The calibration procedure should take less than two minutes to complete for the manual A/C-heater control, and less than twenty seconds for the ATC A/C-heater control. 
When the LEDs or graphics stop flashing, the calibration procedure is complete.

ON Some cases the Flashing light will not stop:---

If the LEDs or graphics continue to flash beyond the two minute (manual) or twenty second (ATC) calibration time.
So here is the problem
These flashing lights indicates that the A/C-heater control has detected a failure and a Diagnostic Trouble Code (DTC) has been set. 
On such cases the vehicle needs to be scanned by OBD tool to retrieve the error codes. These error codes will tell or indicate what part is causing the problem.

IMP NOTE:-- The LEDs or graphics will continue to flash even after the ignition switch is cycled Off and On, until a successful calibration is completed or until the vehicle has been driven about 13 kilometers (8 miles.That flashing is normal.

These details will help.

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