Preparation For Test

The manual (visual) function tests permits checking the function (operation) of all components of automatic climate control (ACC) system. Additional tests for finding the cause of the fault are only required in the event of deviations from the functions or air outlets shown here.
- Run engine at idle and at operating temperature during entire test.
- Open swivel inserts for air outlet center, left and right.
- Remove glove box.

NOTES:
1. At room temperatures >25°C (77°F) the cycling of the monovalve cannot be readily shown during second and sixth test. For this purpose, the vehicle interior should be cooled down to approx. 22°C (72°F) with doors, windows, and top closed.
2. Other tests can be made with an adapter for ACC 126 589 03 21 00.

ACC Push-Button Control Panel:

3. Illustration of special operating conditions:
Only one button at a time should be pushed, on principle. The operating descriptions described below are therefore not included in test scope. They are mentioned only to assist customers if such a condition has been established by chance. No damage will occur, even if the vehicle is driven for an extended period of time.
a) All buttons "a" - "e" not pushed:
Operating condition similar to "c", but the lowest automatic blower stage will be raised to 3rd stage.
b) Button "e" pushed in combination with another button:
System is always in switched-off condition.
c) Buttons "c" and "d" pushed at the same time:
Operating condition similar to "d", but 3rd blower stage will drop to 2nd stage.
d) Buttons "b" and "c" pushed at the same time:
Operating condition similar to "b", but 3rd blower stage will drop to 2nd stage.
e) Buttons "a" and "b" pushed at the same time:
Operating condition similar to "a", but legroom flaps will also be open.
f) Operation of button "a" (DEF) will always predominate in relation to selector dial and blower.
g) Buttons "b" and "d" pushed at the same time:
Function similar to "b", but compressor will be switched off.

ARROWS IN TESTS 1 - 12
Shaded = Outside Air
Solid = Cooled Air
White = Heated Air
White (small) = Air Outlet (warm)