kabir

Hi ,i have a 57 plate q7 4.2 tdi my prob is that the aux heater turns it self on and stays on sometimes all night ,if i hear it on i take the car for a drive and then when i park up the heater is off but within an hour or so it comes back on again it is bloody driving me MAD ! any ideas please

Edd W

Check the settings in the MMI.

kabir

Thanks Edd ,The car is at the garage now ,the heater was on all night and drained the battery had to jump start it ,ive fingers crossed the guy can sort it I will mention the MMI to him ,thanks for replying

Shahnuaz Meah

I had this exact same issue, turnes out the ecu on the auxhiliary heater malfunction...i tried everything and calling every including webasto who make the thermo top c aux heater for audi and even they wont touch it...Any way, i got around it but just pulling the fuse for the aux heater out and left it out until i got round to replacing the aux heater. The ecu's on these things go quite often are very expensive to replace...pull the fuse out and live with it or as we are coming up to winter source a second hand one from fleabay and get it put on and coded in using vag com like i did. The aux heater being off doesnt do anything other than give u heat before the engine warms up...it cost me 120 for the aux and 100 for labour at a local vw audi specialist.