For those experiencing throttle position sensor issues, here is something to try before replacing that throttle body: I was experiencing limited performance mode with codes related to the throttle position sensor. It was random, though occurring on a daily basis, requiring a clearing of the codes to get out of limited performance mode. The throttle body had been changed 3 years earlier for the same problem. What I decided to do was to, with the car off, simply step on the accelerator pedal multiple times, in effect, operating the potentiometers in the tps throughout their full range. Most potentiometers have as part of their variable resister set up a "wiper" type device to clear the contact surface, so operating the pot throughout its entire range can clear corrosion or debris that is interfering with contact of the variable resister. Well, this did the trick, I have gone a week without any problems and no codes.

It won't work for every problem, but its worth a try before spending money on a rebuilt or new throttle body. Moral of the story is that I must need a heavier foot!

 

Oxidation: critical for heat, but tough on electronics . . . This could put trusty old ASI out of business.

 

This was my suggestion in a thread a while back. I do it all the time now and have not had an issue ... in ... could be two years.

I'm not sure how most TPS are designed. The one Jaguar uses in the later 308's is actually two resister pathways (not sure of the correct term) -- I believe one is increasing and the other decreasing. The computer monitors both legs ... I guess they have it set up this way for safety -- since this sensor is vital to control the cruse control and the ASC functions. I know the early Ford sensors only used one pathway.

So unfortunately -- a problem on only one side will get an error. That could be why it is not available on the aftermarket.

I was at the dealer one day and the tech showed me the diagram and explained the operation.