Throttle body position switch
 

Hi all,

had my car on the diagnostics which read up faulty throttle body position switch 240 quid later put a new one in and it still had the rev problem until i fiddled with the position of the position switch where it seems to be ok now. Would the position of the switch be enough to trigger the diagnostics (so have just wasted money on a new one) or would it be faulty and in the wrong position?

Thanks
Jamie

The TPS being misaligned on the body shouldn't trigger a DTC. That should only come on if the signal from the sensor drops out completely.

I wouldn't be at all surprised to find that the track on the old one had worn around the idle position - and was dropping out there.

If you check the service manual for your car you'll find that there's an acceptable tolerance value for "idle" on the sensor - you can read the value either direct off the ECU pin with a voltmeter, or via its digital value on a select monitor emulator.

Chances are that when you were fiddling with the position, you've got it in that area already but it wouldn't do any harm to check if you've got the equipment to do it.

ok thank you, the diagnostics are with a friend so for tonight is there a way i can find out the position it should be in? The car did function ok but was getting bad mpg and cut outs sometime can this still mean the signal from the old sensor was totally lost but still make the car function? thanks