Purpose Of The System
The E60 IHKA system is designed using the same criteria as the E65. There are technological improvements as well as new or modified functions. As with E65, the design objectives were to meet the requirements of customers worldwide for heating and cooling capacity.
New System Components And Features
- Condensation Sensor (Mist Sensor) - The Condensation sensor evaluates the humidity level of the windshield area and implements control measures to reduce windshield fogging.
- New Bus System - The Local Interconnect Network (LIN Bus) connects all 9 step per motors and the blower controller.
- Modified Control Concept (As compared to E39) - Similar to E65, there is a reduction in the number of primary controls. The temperature and air volume are controlled by rotary knobs. Extended air conditioning functions such as air stratification are selected and activated by means of the controller in the CID.
Scheme 162
Additional System Features
- Modified Display Concept - The Scope of display elements for the extended AC functions in the CID are similar to those in the E65. The required fan and temperature settings are not shown in the CID. The set values for temperature and air volume can be read from scale rings on the IHKA panel. Air distribution is set by means of the controller in the CID.
- Elimination of LCD Display - The LCD display from the E39 has been eliminated.
- No Bowden Cables - All flap positions are set by stepper motors which are controlled via the LIN bus.
- Separate Footwell Flaps for Left and Right
- Separate Ventilation Flaps for Left and Right
- New Suction Action Blower arrangement - The new blower arrangement allows for a more compact IHKA housing. The blower is arranged behind the evaporator. The heat exchanger for the heating system is positioned at right angles with respect to the evaporator and is arranged over the blower. The blower motor and blower motor housing can be removed without removal of the complete dashboard assembly.
- Clutchless A/C Compressor - The clutchless compressor is externally actuated and output regulated. The component and operation are carried over from the E65.
- AUC-2 Sensor - The AUC sensor is carried over from the E65.
- Solar Sensor - The solar sensor is located in the center of the dashboard and is also carried over from the E65/E66.
Scheme 163
System Components
The E60 Climate Control System consists of the following components
Components Located In Passenger Compartment
- IHKA Control Panel/Module
- Condensation (Mist) Sensor
- Solar Sensor
- CID and Controller
- Face Vent Temperature Sensor
Components Located In (Or On) IHKA Housing
- 9 Stepper Motors (all on LIN Bus)
- Blower Motor with Controller (on LIN Bus)
- Evaporator Temperature Sensor
- 2 Heater Core Temperature Sensors (Left and Right)
- Heater Core (Heat Exchanger)
- Evaporator
- Expansion Valve
Components Located in Engine Compartment
- A/C Compressor
- AUC Sensor
- Water Valves
- Auxiliary Water Pump
- A/C Condenser (with Integrated Receiver/Dryer)
- Auxiliary Cooling Fan
- A/C Pressure Sensor
- Refrigerant Lines
- Microfilter System
IHKA Control Panel/Module
The IHKA Control Panel/Module controls the following functions
- Desired Temperature Setting, Left/Right
- Air Volume (Automatic and Manual Blower Settings)
- A/C On/Off Switch
- Recirculation Control (Including AUC)
- Rear Window Defogger
- MAX A/C
- Defrost Function
There are additional functions such as air distribution (defrost, face and footwell) and air stratification that are selected and controlled with the controller in the CID.
Scheme 164
Scheme 165
Remove IHKA panel and connect breakout boxes
Record the steps and fasteners (if any) used to remove the IHKA control panel/module
List part numbers of breakout boxes and cables used
List the connector numbers for the following connectors
26 Pin
12 Pin
3 Pin
Condensation Sensor
The condensation sensor is new to BMW climate control systems. The sensor is used to measure air humidity and temperature in the windshield area.
This information is sent to the IHKA control unit via a digital signal with a varying frequency. This information is evaluated by the IHKA control module, which then implements a series of countermeasures to prevent windshield fogging. The countermeasures are implemented in the following sequence
Scheme 166
| Measures | Action |
|---|---|
| 1 | Defroster flaps opened further |
| 2 | Recirculating air/AUC/automatic recirculating air switched to fresh air |
| 3 | Partial fresh air in connection with recirculating air/AUC/automatic recirculating air switched to fresh air |
| 4 | Minimum evaporator temperature (progressive EVAP temperature de-activated) |
| 5 | Blower air volume increased |
| 6 | Footwell share decreased |
| 7 | Temperature setpoint increased |
MEASURES AND ACTION
These measures are implemented one after another until windshield fogging is eliminated. Further steps are initiated if one measure proves to be ineffective. After successfully eliminating windshield fogging, the measures are gradually cancelled in steps.
The sensor is located beneath the RLS on the windshield below the cover for the base of the rear view mirror. A special locating tool is used to install the new sensor, this tool is supplied with the replacement sensor. The sensor is affixed to the windshield with an adhesive. If the sensor needs to be removed from the windshield it must be replaced.
Scheme 167
Solar Sensor
The solar sensor is located in the center of the dashboard to the right of the center speaker grill.
The solar sensor operation is identical to the past models such as E65/E66.
As on previous models, the solar sensor signals will influence blower output, air stratification and ventilation flap operation.
Scheme 168
AUC-2 Sensor
The AUC-2 sensor is located on the cooling fan housing at the top. The sensor operation is identical to the E65. The AUC-2 sensor will signal the IHKA to activate recirculation mode when the sensor detects oxidizable gases such as hydrocarbons, carbon monoxide and nitrogen oxides.
Scheme 169
The CID and Controller are used for air distribution adjustments, air stratification and for the parked car ventilation features. The air volume for face vent, foot well and defrost can be adjusted independently for the driver and passenger.
Scheme 170
Scheme 171
Stepper Motors
These stepper motors are MUX5 motors (multiplex motor type 5).
There are 9 stepper motors used on the E60 IHKA system. All motors are connected to the LIN Bus. The LIN bus circuit consists of three wires, power (B+), ground and the LIN bus signal wire.
The stepper motors for the fresh air/recirculating air flaps are designed as high speed motors.
This system does not use any bowden cables for flap actuation.
Scheme 172
Blower Motor With Blower Controller
The blower motor for generating the necessary air volume is fitted in the heater air conditioner. The blower features a symmetrical design and is equipped with two dual suction action radial fan wheels (four flute blower).
The blower controller is mounted directly on the housing of the blower motor. The controller features self diagnosis capabilities and is actuated by the control unit in the IHKA panel via the LIN bus. It is possible to replace the fan motor without the need to disassemble the instrument panel.
Scheme 173
Temperature Sensors
All temperature sensors used in the E60 IHKA system are NTC type. The E60 IHKA system uses the following temperature sensor inputs
- Interior Temperature Sensor - Located in the IHKA control panel faceplate. The IHKA panel also incorporates a sensor fan which is removable and can be replaced as a separate part. The temperature sensor itself is not replaceable separately.
- Ambient (outside) Temperature - The ambient temperature sensor is an NTC sensor which is an input to the instrument cluster. The temperature signal is then sent to the IHKA control module via K-CAN.
- Two Heater Core Temperature Sensors - The Heater core temperature sensors can be accessed by removing the CID. The temperature sensors are used to monitor the temperature of the left and right side of the heat exchanger.
- Evaporator Temperature Sensor - As on previous models, the evaporator temp sensor is used to prevent evaporator freeze-up.
- Face Vent Temperature Sensor - There is one face vent temperature sensor located behind the center face vent. It can be accessed by removing the center face vent, IHKA panel and M-ASK.
Scheme 174
Scheme 175
A/C Compressor
The A/C compressor in the E60 is identical to the clutchless design introduced on the E65/E66
Scheme 176
Pressure Sensor
The pressure sensor is located in the high side pressure line between the condenser and the evaporator near the passenger side strut tower.
The sensor sends the IHKA control module an analog signal between 0.4V and 4.6V as a representation of system pressure.
The 5V supply is provided by the IHKA control module and the sensor current consumption is < 20mA.
Scheme 177
Water Valves
The water valves on the E60 are of the same design as used on previous models. The valves are normally sprung open and are pulse width modulated by the IHKA control unit. The IHKA control unit controls the valves via the B+ circuit, both valves are grounded at a common location. The valves are powered closed by the IHKA module when full cooling is needed. They are located on the driver's side strut tower.
Scheme 178
Auxiliary Water Pump (ZWP)
The auxiliary water pump is mounted on the drivers side frame rail near the alternator. The ZWP enhances hot water flow through the heater core particularly when the engine is idling.
Scheme 179
Microfilter System
An activated carbon microfilter is fitted on the E60 IHKA system. Microfilter replacement intervals are based on CBS data. Based on operating time and operating parameters, the "filter condition detection" system determines the load status of the filter without additional sensors. In this way, due dates for filter service are calculated together with other components. After changing the filter, the CBS system must be reset via the instrument cluster or in the tester (DISplus/GT-1).
The following are recorded parameters for determining the filter load status
- Blower Voltage
- Outside Temperature
- Sun Intensity
- Mileage
- Road Speed
- Rain Intensity
- Day Counter
Scheme 180
AC Housing Installation
Particular care must be taken when mounting the air conditioner on the inner side of the bulkhead to ensure the seals are fitted correctly. The butyl beading on the seal provides a tight seal with the bulkhead. When assembling, make sure the repair instructions are followed precisely. Failure to adhere to the procedure could result in interior water leakage.
Scheme 181
Scheme 182
In the same way as for the seals, particular care must be taken when installing the filtered air duct and the filter compartment covers. Secondary (unfiltered) air may be drawn in from the engine compartment if the seal between the duct components is defective.