BMWAG
Electrical troubleshooting manual
5 Series - E34 (518i, 520i, 525td, 525tds, incl. touring) Schematics Model year 1994

Automatic climate control (IHKA)
Scheme 6450.0

Pin Assignment
A=X61026-pin, white B=X611 26-pin, green
C=X61326-pin, blue
D=X61426-pin, yellow
Pin Assignment X610
PinTypeDescription/FunctionConnection
1ASignal, rear compartmentRear actuator motor
2ASignal, rear compartmentRear actuator motor
3ASignal, rear compartmentRear actuator motor
4ASignal, rear compartmentRear actuator motor
5ABlower ONBlower output stage
6ASignal, air conditioning ONA/C relay
7ASignal, rear window defogger ONRear window defogger relay
8ASignal, compressor ONPressure switch B8y
9not used
10not used
11not used
12ETerminal 30Fuse
13ETerminal 30Fuse
14ASignal, recirculated airRecirculated air flap motor
15ASignal, recirculated airRecirculated air flap motor
16ASignal, recirculated airRecirculated air flap motor
17ASignal, recirculated airRecirculated air flap motor
18AActivation, lightsIHKA operating unit
19AActivation, rear window defogger lightsIHKA operating unit
20E/ATxD diagnosis lineDiagnostic connector
21AActivation, left water valveLeft water valve
22AActivation, auxiliary water pumpAuxiliary water pump relay
23AActivation, right water valveRight water valve
24not used
25ETerminal 30Fuse
26ETerminal 30Fuse
Pin Assignment X611
PinTypeDescription/FunctionConnection
1ASignal, left footwellLeft footwell actuator motor
2ASignal, left air mixingMixing air flap motor, left
3ASignal, left air mixingMixing air flap motor, left
4ASignal, left air mixingMixing air flap motor, left
5ASignal, left air mixingMixing air flap motor, left
6AActivation, fresh airFresh air flap motor
7AActivation, fresh airFresh air flap motor
8AActivation, fresh airFresh air flap motor
9AActivation, fresh airFresh air flap motor
10not used
11not used
12not used
13not used
14ASignal, left footwellLeft footwell actuator motor
15ASignal, left footwellLeft footwell actuator motor
16ASignal, left footwellLeft footwell actuator motor
17ASignal, defrostDefroster flap motor
18ASignal, defrostDefroster flap motor
19ASignal, defrostDefroster flap motor
20ASignal, defrostDefroster flap motor
21ASignal, left-hand ventilationVentilation flap motor
22ASignal, left-hand ventilationVentilation flap motor
23ASignal, left-hand ventilationVentilation flap motor
24ASignal, left-hand ventilationVentilation flap motor
25not used
26not used
Pin Assignment X613
PinTypeDescription/FunctionConnection
1MGroundGround connection
2MGroundGround connection
3not used
4ASetpoint, left-hand temperatureIHKA operating unit
5ASetpoint, blowerIHKA operating unit
6AInterior sensor blower motorInterior sensor blower motor
7EOutside temperatureOutside temperature sensor
8ASetpoint, right-hand temperatureIHKA operating unit
9EEvaporator temperatureEvaporator sensor
10AVoltage supply of actuator motorsAll actuator motors
11AVoltage supply of actuator motorsAll actuator motors
12ETerminal 15Fuse
13ETerminal 15Fuse
14MGroundGround connection
15MGroundGround connection
16MGround for all sensorsAll temperature sensors
17ASetpoint, mixing airMixing air actuator
18ELeft heat exchanger temperatureLeft heat exchanger sensor
19ETerminal 30 hAlternator
20MGround for potentiometerIHKA operating unit, mixing air control
21EInterior temperatureIHKA operating unit
22ERight heat exchanger temperatureHeat exchanger sensor
23AVoltage supply of actuator motorsAll actuator motors
24AVoltage supply of actuator motorsAll actuator motors
25ETerminal 15Fuse
26ETerminal 15Fuse
Pin Assignment X614
PinTypeDescription/FunctionConnection
1ASignal, right footwellRight footwell actuator motor
2ASignal, right footwellRight footwell actuator motor
3ASignal, right footwellRight footwell actuator motor
4ASignal, right footwellRight footwell actuator motor
5ESignal, recirculated airIHKA operating unit
6ESignal, defrostIHKA operating unit
7ESignal, rear window defoggerIHKA operating unit
8ESignal, normal programIHKA operating unit
9ESpeedometer A signalInstrument cluster
10ARxD diagnosis lineDiagnostic connector
11AVoltage supply for defrost/ independent heatingIHKA operating unit
12AVoltage supply, interior ventilation/ recirculated air/independent heatingIHKA operating unit
13AVoltage supply footwell/recirculated air/ rear window defoggerIHKA operating unit
14ASignal, right-hand ventilationRight ventilation flap motor
15ASignal, right-hand ventilationRight ventilation flap motor
16ASignal, right-hand ventilationRight ventilation flap motor
17ASignal, right-hand ventilationRight ventilation flap motor
18ASignal, right air mixingMixing air flap motor, right
19ASignal, right air mixingMixing air flap motor, right
20ASignal, right air mixingMixing air flap motor, right
21ASignal, right air mixingMixing air flap motor, right
22not used
23not used
24not used
25not used
26not used
E = Input, A = Output, M = Ground