F31 heater problem

[Lilpheesch]

Hi all,

Wondering if anyone else has had this problem, or can recommend a fix? Bmw F31 -2013 -330d m sport.

When the heater is set to 16.5 degrees or higher the heat in the cabin becomes unbearable. With the heater set to 16 degrees it blows extremely cold. There is no middle ground. The little dial below the centre consol vents is centered as well.

Any help would be greatly appreciated before I cook/freeze to death on the way into work.

[RUSSELLM]

I was thinking it could be a blend issue, as in a motor stuck.

But the fact that 16C makes it blow cold, leads me to think the motors are probably working.

Without venturing to my car, I presume 16C activates the low mode (max air con). If so, I would imagine you’ve got a cabin temperature sensor that either has no output, or is under reading.

If there’s no DTC’s stored, you’re going to need access to live HVAC information.

FWIW, my usual repair for anything they looks like a BS fault, is a disconnect/reconnect on the battery

Edited by RUSSELLM on Wednesday 27th November 15:09

[Lilpheesch]

Thanks for the help. I'll try that as soon as it stops lashing down with rain (could he a few days at this rate). Is it as simple as disconnect battery and reconnect or will that throw up all sorts of faults and alarms? I know bmw aren't too keen to let people sort their own problems out.

[RUSSELLM]

If you do decide to disconnect the battery, it might log some extra DTC’s. You could minimise that slightly, by waiting 10 minutes for the extended ignition to die, before hand.

I normally just remove the negative lead for a few seconds.

That or get the codes and data read, by someone with the correct equipment.

I presume it’s not under warranty at the moment ?

[BFleming]

I'm betting that disconnection & reconnection of the battery will not help you. Read the codes (there are several ways of doing this, but a generic OBD2 reader will not help). I use INPA to identify the modules, then ToolSet32 (part of Ediabas) to read the modules. This needs a DCAN cable and the software that comes with it. There are other options, possibly using an ESYS cable and ISTA / Rheingold, I have no experience of them.