[Stevesimpson94]

I set my climate control to 23°C (England) and select auto.

The heater starts blowing warm air and the air temperature in the cab raises to what feels like 23°C which is great.

But....

After about 10/15mins all the heater vents start to blow cold. Including foot vents and the centre vent. If i increase the temp to 25°C it gets warmer again but then after 10/15mins starts blowing cold again.

Is this normal? If not WTF is going on. i just want to be able to leave it on 23 without getting hypothermia, all engine temps and water levels are spot on.

Its as though its timered to start blowing cold after its reached the desired temp on the climate control. Its not like any other climate control system iv used before.

Please some shed some light on this, tell me how yours works.

cheers

steve

 

[markusmarkus]

No, that's not normal. Is the AC coming on? Is the AC "snowflake" off?

There's a temperature sensor in the heating coil. The system is designed to stop coolant from flowing through the heater coil if the coil temperature gets too high. I've seen a couple of posts where the owner replaced the sensor and the heat started working properly. Also, there's a cabin air temperature sensor in the climate control module. That could be going bad.

 

[Stevesimpson94]

No the air con doesnt come on because i never have it selected. But when i do have it selected i can hear it dropping in and out as though it is working correctly.

So lets conclude; air con off - heater drops cold after 10/15mins as though the valve is shutting not allowing hot water through the coil.

air con on - i can hear the air con coming in and out accordingly.

SO ... possible temp sensor in heater coil or cabin temp sensor. brilliant.

How could i check these sensors? Any way of INPA diagnosing the hole climate control system?


Thanks for you input mate

 

[markusmarkus]

I'm not familiar with inpa software but it may be able to check that sensor. You might find someone with the same model year car and swap IHKAs to see what happens. You could shotgun it and replace the sensor. Unfortunately realoem doesn't show that sensor. It doesn't show the AC evaporator temp sensor either. Check with the dealer.

 

[Bali]

How could i check these sensors? Any way of INPA diagnosing the hole climate control system?

Yup, INPA is very useful for diagnosing IHKA issues.
https://goo.gl/images/hHmC1J
https://goo.gl/images/B9N1QO

Read this document as well.
http://bmwcarx.com/web/DocumentosBMW/E46ControlClimatico.pdf