Auxiliary Air Heater, Checking

Auxiliary Air Heater, Checking

The electric auxiliary air heater is available in different versions (with and without Auxiliary Air Heater Control Module (J604) ).

• On vehicles with Diesel engine manufactured up to November 2006 (running change in production), auxiliary air heater heating element (Z35) is activated via the auxiliary air heater control module (J604). Only on these vehicle is it possible to perform Guided Fault Finding on the auxiliary air heater using Vehicle diagnosis, testing and information system (VAS5051B) in "Guided Fault Finding" function.

• On diesel vehicles built from November 2006 (running change) have a 3-stage Auxiliary Air Heater Heating Element (Z35) which is controlled by a relay from the engine control module. Check using Vehicle diagnosis, testing and information system (VAS5051B) in "Guided Fault Finding" function.

• Auxiliary Air Heater Control Module (J604) is available in different versions. Pay attention to precise assignment on replacement. Refer to Electronic Parts Catalog (ETKA).

• The "Guided Fault Finding" for the auxiliary air heater is to be performed using vehicle diagnosis, testing and information system (VAS 5051B) in "Guided Fault Finding.

• Auxiliary Air Heater Control Module (J604) is installed in Auxiliary Air Heater Heating Element (Z35) (cannot be replaced individually). Auxiliary Air Heater Heating Element is installed in air distribution housing of heating & A/C system. Refer to => [ Auxiliary Air Heater Heating Element (Z35) with Control Module (J604) ] Auxiliary Air Heater Heating Element (Z35) With Control Module (J604) and => [ A/C Unit ] A/C Unit.

• Depending on version of Climatronic Control Module (J255) , individual DTCs possibly cannot always be erased immediately. For these vehicles, switch off ignition and interrupt voltage supply to Climatronic control module (terminal 30 in connector D) for approximately 30 seconds.

• Depending on version of Climatronic Control Module, certain settings and codings cannot be transferred immediately. If necessary, lock vehicle and let it stand a minimum of 30 minutes (this allows Data bus system to switch into "Sleep Mode" and once Data bus system awakens these new settings can be transferred).