Components Actuated By A/C System, Electrical Test

Various electrical components of the vehicle (for example, Rear Window Defogger -Z1- and heated seats) which do not belong, are actuated by the Climatronic Control Module -J255- control head (or the Rear A/C Control Head -E265-). In the case of the rear window defogger -Z1-, an activation request, for example, is first transmitted via the data bus to the Data Bus On Board Diagnostic Interface -J533 - and then to the Comfort System Central Control Module -J393-. The Comfort System Central Control Module -J393- then activates the rear window defogger -Z1- via the Rear Window Defogger Relay -J9-. Refer to the appropriate WIRING DIAGRAM. The electric testing of the components and of the Comfort System Central Control Module -J393- is described. Refer to Vehicle Diagnostic Tester in "Guided Fault Finding"  function.

Certain Air Conditioning (A/C) system functions can be switched on and off via the MMI (Multi Media Interface) under the "A/C system" function in the "car" / "car systems" menu. The A/C system control can also be influenced via presettings in the MMI (Multi Media Interface) under the "A/C system" function in the "car" / "car systems" menu. Therefore, first check the presetting in the MMI in the case of a problem with these components. Refer to Infotainment/MMI Operating Instructions.