I have the dreaded heater problem whereby it will go from the extreme cold to extreme hot with nothing in between.

I have changed the V68 temp flap motor but the same problem persists (ps you can change the motor WITHOUT taking the dash out, just remove the lower trim panel).

I have run basic settings on VAGcom and interestingly the only value it ever shows is 255, i understand this should show 0 as standard.

I think the AC switch and recirc buttons work, VAGcom shows the compressor comes on with the AC switch and the recirc switch definitely works as you can hear it. Strangely though all the values on basic setting show 255 which seems odd to me.

Where is the next place i should look? Does it look like the control panel is knackered even though only it is the temp giving me issues?

I desperately need help with this guys as the motor cost me £80 and now seems like a waste of money and i definitely wont go to the stealers!!

Thanks in advance from a desperate man!!

I thought there was a temperature sensor thing inside the system which often fails?

Isn't it somewhere underneath the centre dashboard deep in the ventilation system?

I read about it on here when I did a search, because I find that my car also sometimes randomly gives a blast of very cold air even when set on hot.

You need to run the motor through basic settings if you ve not done that already, other wise you have the motor fitting in the incorrect position, 255 means it cant determine where it is, which in turn means the above

I've run the motor through basic settings but it just stays stuck on 255.

I can watch the motor as i adjust the temperature control, it goes to cold, then if i click it 2 steps up it goes fully the other way. It's like the motor has only 2 steps programmed.

It doesn't sporadically switch between hot and cold without being touched, the motor just doesn't pick up the middle positions between hot and cold.

Another wierd thing is that the fault code for the V68 motor has now cleared and i'm left with one for the recirc motor as below, i know that motor works though.

2 Faults Found:

01596 - Motor for Outside/Recirculated Air Flap (V154)

30-00 - Open or Short to Plus

01596 - Motor for Outside/Recirculated Air Flap (V154)

55-00 - Adaptation Not Successful

Would this still point to the temp sensor? And where is this mysterious sensor?

I thought there was a temperature sensor thing inside the system which often fails?

Isn't it somewhere underneath the centre dashboard deep in the ventilation system?

I read about it on here when I did a search, because I find that my car also sometimes randomly gives a blast of very cold air even when set on hot.

There is indeed, and it gets clogged up with dust, so it can't tell the temperature correctly and just does either hot, or cold air meaning it can modulate the temperature.

It's located on the heater control panel. By the drivers side, there is a little grille type thing next the the A/C buttons. If you pull that panel out you can get to the sensor which is recessed in there. To clean it just blow on them or something gentle. To get the panel off, pull from the bottom and it just prises up. When re-attaching it makes it easier if you push the base of the cubby hole up slightly so there is more room for it (will make sense when you get there).

Alternatively, try placing a hoover nozzle over the grille, might clean it, but I have never tried this way.

HTH, Joe

Thanks for the replies.

I have checked the temp sensor on the panel and cleaned, still no joy though.

More symptoms - The motor responds sporadically when going up the temp control, but will not respond in the way down until fully cold. When it is at fully cold the motor will click like it wants to go further, but can't. I get the impression that will burn the motor out sooner or later!

I have now run about 20 Basic settings, strangely one of them worked and showed zero. The rest were resolutely on 255.

This leads me to believe it is the panel. How does VAGcom control the motor? Is it via the panel or should VAGcom still correctly control the motor if the panel is malfunctioning?

Sounds like a comms problem with the heater control panel. Adaption not completed usually means either the motor is out of sync with the flap gears, or the panel is U/S.

If it's a comms problem, which sounds most likely to me, does that mean a new panel or an issue with the actual wiring?

If it's a comms problem, which sounds most likely to me, does that mean a new panel or an issue with the actual wiring?

Heater panel is more common failure than wiring, but who knows. I have seen EVAP sensor cause this as well.

Sorry for reviving such an old topic, but have you managed to repair it?

1 hour ago, Corby said:

Sorry for reviving such an old topic, but have you managed to repair it?

 

Looking at scottyboy's profile he hasn't been online since November 2015, so seems unlikely you'll get a reply.