Coolant bypass valve circuit open


Registered User
I've got a "Coolant bypass valve circuit open" Fault on my S3 and reading through here it looks like it could just be some water in the electrical plug connection.

Does anyone have a diagram of the engine or a photo which shows where the coolant bypass valve is on the engine and how to get to it?
Also, not wanting to snap any clips of the electrical plugs, how are they removed, where is the clip and which way do I need to push/pull it?



Registered User
I read it’s the grey plug under the intake, take that with a pinch of salt though, because I couldn’t find it . :)


Registered User
This is what I had as an error code!

2 weeks later car cut out and new water pump and new ecu!

You had a coolant light come on before?

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Registered User
No, I don't have any coolant loss.
I have just removed, cleaned and re-seated the connector, I'll see if the fault reappears... Fingers crossed they just disturbed the connector when they did the gearbox oil recently...