Main Wiring Diagram For A/C System Actuators
Revised A/C units are gradually being installed from MY 2012 (use depends on the vehicle version) (A/C unit part number "8T_ 820 005"). With the introduction of these A/C units, other actuators are also being installed. The actuator different versions can currently be installed on both A/C unit versions (interchanging is currently permitted). Refer To use the Vehicle Diagnostic Tester in the "Guided Fault Finding " function.
On this vehicle, the different actuators (-A- through -N-) on the A/C unit are adapted and activated via a data wire. The different actuators (-A- through -N-) are connected in sequence to the Climatronic Control Module -J255- A/C display and control head via this data wire (LIN Bus). If there is a malfunction on one actuator or in the wiring, this malfunction can lead to different malfunction entries with different malfunction types, using the Vehicle Diagnostic Tester in the "Guided Fault Finding " function. Refer To The Appropriate Wiring Diagram(s).
The number of actuators on the A/C unit depends on the A/C system version (on the "Basis" A/C system there are six actuators, and on the "Convenience" A/C system there are 10 actuators). Refer To The Appropriate Wiring Diagram(s).
The sequence of the actuators in the wiring depends on the A/C version ("Basis" or "Convenience" and on the vehicle version. Refer To The Appropriate Wiring Diagram(s). On vehicles equipped with the "Convenience" A/C system, the Left Temperature Door Motor -V158- is installed, for example, at position -A-. On vehicles with the "Basis" A/C system, the Temperature Regulator Door Motor -V68- is installed at position -A-. Refer To The Appropriate Wiring Diagram(s).
Dependent on the operating condition or the function of the A/C system Guided Fault Finding in which a malfunction appears, the effect of the malfunction and the type of malfunction stored in the DTC memory is different, using the Vehicle Diagnostic Tester in the "Guided Fault Finding " function.
- If there is a malfunction in the actuators sequence (two or more terminals or actuators were interchanged while being installed)
-- If these actuators were improperly adapted during the basic setting and the activation of the doors is incorrect (incorrect assignment)
-- Depending on the adjustment range for this actuator, an incorrect end stop is recognized during the basic setting and this is stored as a malfunction in the event memory, and the basic setting is terminated.
-- If the wrong door moves, then the air flow direction is incorrect. This is not always recognized as a fault depending on the adjustment range of the actuator. Always mark all connectors before disconnecting them and perform a basic setting after connecting them.
- If there is a malfunction in normal A/C system operation, then the following DTC memory entries can result, depending on the type of malfunction.
-- If there is a malfunction in the positive or ground connection to an actuator, then this actuator can no longer exchange information with the Climatronic Control Module -J255- A/C display and control head and this actuator will store this in the DTC memory.
-- If there is a malfunction in the data wire to an actuator (for example, an interruption in the connector to the contact "2" of the actuator -B-), then this actuator and all the connected actuators (-C- through -N-) in the sequence switching after this actuator can no longer exchange information with the Climatronic Control Module -J255- A/C display and control head; this actuator as well as all the other connected actuators will be stored in the DTC memory.
-- If a malfunction occurs in the actuator electronics (for example, in actuator -B-), the actuator -B- can possibly still exchange information with the Climatronic Control Module -J255- A/C display and control head, depending on the type of malfunction, however all the actuators connected after this one (-C- through -N-) will be stored in the DTC memory.
- If there is a malfunction during the basic setting of the A/C system, then the following malfunction entries can result, depending on the type of malfunction.
-- If there is a malfunction in the positive or ground connection to an actuator, (for example to actuator -B-), then this actuator cannot exchange information with the Climatronic Control Module -J255- A/C display and control head and it will not be recognized during the basic setting. During the basic setting, all the actuators from the last actuator beginning with -N- are re-allocated and re-assigned; this actuator is no longer in sequence. The Climatronic Control Module -J255- A/C display and control head recognizes that an actuator is missing and saves the first actuator in the sequence switching as missing (for example, on left-hand drive vehicles equipped with the "Convenience" A/C system, the Left Temperature Door Motor -V158-); moreover, the malfunction will display as "Automatic Addressing Malfunctioning" and possibly by certain actuators "Upper or Lower Values Exceeded".
-- If there is a malfunction in the data wire to an actuator (for example, an open circuit in the connector to contact "2" of actuator -C-), this actuator and all connected actuators in the sequence switching after this one can no longer exchange information with the Climatronic Control Module -J255- A/C display and control head, and these actuators are not recognized during the basic setting. During the basic setting, all the actuators from the last actuator beginning with -N- are re-allocated and re-assigned; these actuators are no longer in sequence. The Climatronic Control Module -J255- A/C display and control head recognizes that several actuators are missing (only actuators -B- -A- are recognized and incorrectly assigned and adapted as the Airflow Door Motor -V71- and Recirculation Door Motor -V113-). All other actuators (for example, on vehicles equipped with the "Convenience A/C unit" A/C system, from the Right Footwell Door Motor -V109- up to the Left Temperature Door Motor -V158-) are stored in the DTC memory as missing and the malfunction is displayed as "Automatic Addressing malfunctioning".
-- If a malfunction occurs in the actuator electronics or during the basic setting (for example, in actuator -C-), this actuator may still be able to exchange information with the Climatronic Control Module -J255- A/C display and control head, depending on the type of malfunction. However, no data can be exchanged with all actuators connected after this one (up to actuator -N-). The Climatronic Control Module -J255- A/C display and control head recognizes that several actuators are missing (only actuators -C- up to -A- are recognized and incorrectly assigned and adapted as Recirculation Door Motor -V113-, Airflow Door Motor -V71- and Right Footwell Door Motor -V109-). All other actuators (for example, on vehicles equipped with the "Convenience A/C unit" A/C system, from the Right Center Vent Motor -V111- up to the Left Temperature Door Motor -V158-) are stored in the DTC memory as missing and the malfunction is displayed as "Automatic Addressing malfunctioning".