16v ABF throttle body switch, what does it do?

[Adezmk3]

Hi,

Ok, so there is a little switch on the throttle body (16v ABF) which acts in the same way as a brake switch in that when the throttle is closed, the switch is depressed, and when the throttle is open, the switch is 'unpressed' as it were. I suspect it is to directly tell the ECU when the throttle is in the fully closed position.

Does anyone know exactly what it does?

Mine has come unstuck/fallen off the side of the throttle body, I have temporarily cable tied it in so it isn't flapping about inside the engine bay, so it is not operating with the opening and closing of the throttle for the time being.

I suspect the main outcome of this is fuel consumption may be increased as a result, but obviously the car still drives fine (since when the throttle is open the switch is unpressed anyway).

Any ideas??

Thanks

[itavaltalainen]

will look this up but thinking it is to tell ecu to shut off fuel when you lift off completely and engine is above its normal idle speed (I think it does not inject fuel above say ~1k rpm when you fully lift off).

Do you get a bit of 'bang bang' from exhaust when you're just sailing her? That would indicate that it is injecting fuel when it need not.

[itavaltalainen]

just looked it up. the switch is responsible for idling as thought.

replacement requires alignment of the TB though. you need to measure the distance from throttle to the top edge of throttle body (when fully closed) and once you've replaced switch the throttle needs to be the same distance as before (tolerable is measured distance + 0.5mm only).