Coolant warning light?

[Rikki Kitto]

OK just spent an hour reading through old threads about this issue, lots of good info but just need a bit of input to clarify what's next.

If all levels and temps are fine but warning light still comes on is it OK to run the car to test when rad fan kicks in etc.

[tajgreidotu]

are u sure its the coolant warning?

If yes, then it should be a expansion bottle faulty sensor or shortcircuit in the wiring harness

[Rikki Kitto]

Just bought a new bottle and cap from Audi

[Condor]

Just bought a new bottle and cap from Audi

Did this fix the problem? was the warning light/buzzer on all the time? I have a similar problem at the moment, the warning lamp/buzzer is NOT on all the time, the coolant level is ok, engine temp ok according to gauges....is there anyway of testing the coolant bottle switch? ..cheers Condor

[mike74]

have you tried unplugging the MFTS to see if that cancels the light?

[Error404]

Could also be MFTS

EDIT: D'oh! Too slow

[Condor]

Could also be MFTS

EDIT: D'oh! Too slow

Thanks guys, No I've not tried unplugging MFTS... warning only comes on when the engines warmed up..and goes out on and off ...I need it to play up when I'm home and can try different things to track down the problem .. the engine doesn't appear to be overheating....
I have found several threads here since posting my original message, seems like this happens quite abit ..

[Fat Audi 80]

If your fan works, watch the temperature gauge and wait for the fan to cut in. If your coolant level is ok and the fan is working there is no danger of damaging your engine.

If this was not doing it before exp bottle change, I would suspect the new sensor.

[domas]

very typical MFTS faulure mode.

did your aircon stop working as well? it did on mine. But the sensor was perfectly spot on, but it did send false overheat signal to ecu and climate ctrl head