Coolant Temperature Sensor or something else?

[Tony Elphick]

I put my '53 plate Passat 1.9Tdi in to Nationwide Autocentres in December last for, amongst other things, to replace Coolant Temperature Sensor which they did, and guaranteed work for 12 months. A couple of weeks ago the Emmissions Control warning came on. So I checked for fault codes with my VAG-COM which came up with 17664 - Coolant Temperature Fault. So I took it back to Nationwide. Their first solution was to remove sensor and clean and replace. They did this and warning light stayed off for about 4 days. Then came back on again. Nationwide say their scanner doesn't pick up any fault codes, but I've cleared the code but the same one reappears. So Nationwide have now replaced the sensor this time, but driving it back from them today the same warning has come on yet again as soon as engine gets up to temperature. Could this be something other than the coolant temperature sensor?

[daveo138]

Is it exactly the same fault?

Mine was telling me it was intermittent, which it was.

The new one might have a slightly different problem if it is happening when it gets up to temp.

I replaced my sensor last week - once I'd located it - and I've got the scars to prove it! Not the nicest job in the world.

[Tony Elphick]

Yes the same code has reappeared on my VAG-COM. I cleared the code yesterday evening and the warning didn't appear when I drove about 8 miles this morning. I'm driving home again in a minute so I'll see if it comes back again!

[Tony Elphick]

EMmissions warning light back on again after engine warmed up again! If it's now had a second new coolant temperature sensor in it, any ideas if it could be something else?

[traumapat]

are nationwide fitting a proper vag temp sensor?