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Diagnosis of automatic temperature control (ATC) without removing it from the car

Diagnosis of serviceability of functioning of the PBX is not possible with the battery disconnected. If you for any reason are going to disconnect the battery, first make this check.

Some of the models of cars of mark Jeep Grand Cherokee equipped with automatic temperature control (ATC), which includes a digital display (display), mounted in the instrument panel. The system allows you to make on-board (without removing it from the vehicle) troubleshooting its input and output circuits and to determine both the current took place earlier failures. Under took place earlier failures meant those who currently have withdrawn, they usually occur as a result of violation of the quality of the electrical contacts, which occurred during the execution of maintenance procedures of any other components.

Control Panel PBX system (bottom) compared to the standard manual panel, equipped with three rotary switches (above).

In the diagnostic mode the same part of the working surface of the display screen, which is used to display the temperature.

The upper left part of the display screen, usually serves for the temperature display (two digits) during fault diagnosis system (shown in the figure - there is no arrow pointing at the man (see. Illustration above)) is used to derive the fault codes (0 to 99).

If the exchange takes place in the system of any malfunction on the display every time the ignition is turned on appears (once lit) error message ("ER").

To enter the diagnostic mode, simultaneously depress the button "AC" and ?�RECIRC?� and hold them down, turn one click clockwise handle thermal management. This turns on (lights) full screen display (segmental check).

When you release the button on the left side of the screen will appear the digital code "00" (the choice of the level of checks).

Now, press one (any) of the above buttons. You should see a figure depicting a seated man, indicating the entrance to the diagnostic mode. If the memory is stored in any of the 64 (1 to 64) fault codes, they will be displayed. Record flashed codes and check them against the card faults (see. Table below), identifying parts of the system, requiring more detailed examination. In the case of code from 25 to 29 before proceeding further checks should be replaced by the module control PBX.

Codes current failures will be erased as you make corrections. To delete the code took place before and faults must be disbanded squeeze both buttons on the panel and hold them for at least 3 seconds. On the removal of the code indicated by the appearance on the display of two horizontal dashes.

Diagnosis PBX system allows you to troubleshoot both the input and the output of its contours. However, if an amateur mechanic can not find the reason for having a place in the database of fault codes (see. Card codes below), the drafters of the Guidelines recommend the owner of the car to ask for advice and assistance in dealer branch.

Code card-board diagnostic system for automatic temperature control (ATC)