1.4TDI AMF High idle


New member
Jun 8, 2021
Huddersfield, UK
Arosa 1.4Tdi
Hi Folks

Just picked up a decent condition 1.4 TDi Arosa (AMF) so joined the derv club!

Hoping some of the brains on here can help me diagnose a high idle issue.

The car idles at about 1200rpm but has no fault codes. This doesn't decrease when up to temperature and the car isn't under any load.

It's just had a replacement throttle position sender from a 1.0 AUC petrol model which looked identical but had a different part number which I thought may have caused the high idle, but have since ruled that out as it idles high with the TPS from another Diesel plugged in as well.

I'm yet to check the measuring blocks on VCDS to see what throttle it's receiving when the pedal is pressed but it does drive fine and it did in the petrol AUC prior to being scrapped so have no reason to suspect that.

I've also changed the coolant temp sensor and that made no difference.

Any other ideas what could be causing this high idle?