climate control BMW 3 SERIES 2003 E46 Model Yar Changes

17
2001 model year changes
IHKA IV
The IHKA system is standard equipment on 530i, 540i/it and M5 models. It is available as
an option for the 525i/it. IHKA has been redesigned for the 2001 E39, it is identified as
IHKA IV. The carry over features from the previous version are:
 Integrated control panel/module.
 Separate temperature control for driver and passenger.
 Air distribution control through the use of 5 “smart” stepper motors and one fast acting
hard wired stepper motor.
 Automatic recirculation control (AUC).
 Recirculation control via MFL.
 “Rest” function for residual heat when engine is not running.
 Service station feature that closes the water valves when stopped to prevent hot coolant
flooding the heater core.
 A/C compressor clutch activation via a final stage control.
 Stratification flap control via a bowden cable.
Please refer to the Climate Control course material ST 054 for a complete functional description of
E39 IHKA
70 0 F 640 F
-+AUTO
A
AUTO
MAX

21
2001 model year changes
IHKA integrated heater and air conditioning case
The E39 IHKA case has been redesigned since 3/00. The E39 and E53 both share the
same case design.
The difference from the previous case is that a single flap (left and right), controls both the
fresh air and recirculation inlets. Ram air is controlled by a separate flap. What makes it
possible to use a single flap for fresh air/re-circ is the semi-circular door; as one inlet is cov-
ered another is opened.
Please refer to the Climate Control course material ST 054 for a complete functional description of
ram air pressure compensation.
1. Stepper motor for footwell
2. Stepper motor for rear compartment, stratification
3. Fresh air/recirculation flap
4. Output stage for blower motor
5. Stepper motor for ram air flap
6. Ram air flap
Stepper motors for the fresh air/recirculation,
defrost and ventilation flaps are located on the
left side of the housing
3
6
4
2
15
Right Side of IHKA IV Case
Ram air and fresh air/re-circ flaps as seen from the engine side of the bulkhead