Testing the TPS, what are the normal values?

[Randell]

what resistance values should i expect from the throttle position sensor on an M30 auto? The bentley doesn't give expected figures for this engine so i'm not sure if what i'm reading is showing a problem or not.

I'm getting a steady 11v on the harness end for both idle and wot terminals, but on the TPS end i get some pretty random resistance figures... at closed throttle i get between 2.5 and 11.5 ohms on pins 4 and 6, and at WOT i get resistance anywhere between 8 and 85 ohms on 4 and 5. it's steady, but the numbers change every time i test it. Is this why the bentley doesn't list the figures?

Opening the throttle at all gives 0 ohms on 4 and 6, and letting off from WOT gives 0 ohms on 4 and 5. To me this seems like it's functioning normally, but can someone please confirm? I want to rule this out of my lumpy idle diagnosis and move onto something else

thanks

[Jeff in MN]

what resistance values should i expect from the throttle position sensor on an M30 auto? The bentley doesn't give expected figures for this engine so i'm not sure if what i'm reading is showing a problem or not.

I'm getting a steady 11v on the harness end for both idle and wot terminals, but on the TPS end i get some pretty random resistance figures... at closed throttle i get between 2.5 and 11.5 ohms on pins 4 and 6, and at WOT i get resistance anywhere between 8 and 85 ohms on 4 and 5. it's steady, but the numbers change every time i test it. Is this why the bentley doesn't list the figures?

Opening the throttle at all gives 0 ohms on 4 and 6, and letting off from WOT gives 0 ohms on 4 and 5. To me this seems like it's functioning normally, but can someone please confirm? I want to rule this out of my lumpy idle diagnosis and move onto something else

thanks

When the TPS is closed you should have zero ohms (100% continuity) between 4 and 6. Same for 4 & 5 at WOT. Anything in between closed and open should be an open circuit. 2 yrs ago i was getting 2-5 ohms at closed throttle and my idle was terrible. I took the TPS apart (pretty delicate work) and cleaned the micro switch so my closed throttle resistance was zero and she idled perfectly.
Good luck.

[Randell]

thanks Jeff, sounds like mine is working in reverse! weird... i'll test it again tonight, but i had a guy from work do a sanity check for me and we both had the same results

i just noticed on the realoem image that the screws that hold the TPS are in slots, hopefully if i can loosen them and rotate the TPS i can recalibrate it somewhat...

http://www.realoem.com/bmw/showparts.do?model=HD22&mospid=47382&btnr=13_0188&hg=13&fg=15

if that fails i'll take it apart and see what i can do

just went down and had a look at the way it's mounted, the philips heads are almost completely stripped out and i can see marks on the mounts where the screws used to sit... looks like someone has been messing with this before!