Heinz I really appreciate your help, especially as this is not your first language and you make an excellent job of explaining.
Perhaps the correct pin on the ecu is noted on the wiring diagram, so I'll set out to track that down and try to work out if the circuit rings out. I agree it seems likely there is something causing it to behave as if the brake is being pressed.
However, if it is a damaged wire, there is still contact some of the time , and always when the car is stationary, so I might not be able to trace it by ringing out.
The switch is normally open, meaning that braking opens the circuit and cuts the signal, and thus the fuel. If there's a broken wire, there would be an intermittent open circuit to the ecu, so it could momentarily cut the fuel. That checks out.
But I'm not sure what you mean by the "MAF removed" test you have suggested.
Are you saying that, if the car drives in emergency mode, the fault cannot be in any of the circuits which support emergency mode, and must be elsewhere?
By the way, I've forgotten-are you still getting this problem?
Does anyone know what is done at the service that might have triggered this fault?
Last edited by SFG; 23/05/20 09:44 PM.
