water BMW X5 2001 E53 Workshop Manual

18
IHKR Operation
IHKR system operation is as follows:
• Temperature Control - The desired interior temperature is set with the rotary knob on the
control panel. Control of the interior temperature is carried out electronically by the con-
trol module’s cycling of the water valve to regulate coolant flow through the heat
exchanger.
• Air Distribution - Air distribution is set mechanically through the use of gear linkages and
bowden cables. The air can be set for:
- Footwell or blended between footwell/face vent or footwell and defrost
- Defrost or blended between footwell/defrost or defrost/face vent
- Face vent or blended between face vent/footwell or face vent/defrost
• Blower Control - Blower fan speed is controlled through a final stage with infinitely vari-
able speed control.
The push buttons on the control panel are used to:
• Switch between fresh air and recirculating air inlet modes
• Request for A/C activation
• Activation of the rear window defogger
45
80 72
TEMP
0
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45
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TE MP
M
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6
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DME
M
KL31
KL30
KL15
Fan Speed
Request
A/C Compressor
Recirculation
Rear Defrost
Temperature
Control
Evaporator
Temperature SensorWasher Jet Heater
Blower Relay
Blower
Blower Motor Ouput Stage
M
Rear Window Defoger Relay
Aux. Fan Speed Relay Control
Water Valve
Fresh Air Flap Motor
IKE
DME
Compressor Control
Aux. Fan
IHKR
K-Bus
Refrigerant Pressure Sensor
C
A
N
DIS & Modic
IHKR IPO
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Climate Control System (IHKA)
The IHKA is standard equipment on the X5 with the M62 engine and optional equipment
on the M54 version. The IHKA system is taken from the E39 sedan and includes all func-
tions and features of the IHKA currently installed in the E39.
Features of the IHKA system include:
• Integrated control panel/module.
• Separate temperature control for the driver and front passenger.
• Air flap control through the use of bussed stepper motors.
• Automatic Recirculation Control (AUC).
• Recirculation air flap control from the MFL.
• “REST” function for residual heat when vehicle is stopped.
• Service station feature that closes the water valves when stopped to prevent hot water
circulating into the heater cores.
• A/C compressor clutch activation through a final stage control.
• Center face vent stratification control through a bowden cable.
• Separate blower motor for rear passenger compartment
The rear blower motor is located below the center storage box behind the center air outlet
grilles. The blower speed control is mounted in the panel below the outlets. Cool or strati-
fied air is available at the center outlets.
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Drivetrain
The transfer case, driveshafts, final drives and half shafts make up the drivetrain assembly.
The transfer case is always mounted in the same position on the X5. This applies to other
markets and future models that will utilize different transmissions for different engine con-
figurations. With these models, the transmission tail shafts will be modified to match up with
the transfer case.
The rear driveshaft is a two piece unit using a center bearing, while the front drive shaft is
a single piece that is splined to the transfer case and bolted to the front differential.
The breather vents for both differentials and the transfer case are mounted higher up on the
chassis to prevent water from entering if the vehicle is driven off road through water. The
front breather passes up into the engine compartment and is mounted under the left side
ignition coil cover. The rear breather passes along the under side of the body and is mount-
ed behind the left side wheel arch cover. The breather vent for the transfer case is mount-
ed up high in the driveshaft tunnel.
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