Is it possible to have a bad TPS even though the voltage check looks okay? I keep getting the "code 23" and can't figure out why. I just replaced the MAT sensor and it didn't help. The car runs fine other then the TCC not locking. The check engine light comes on even if the car just sits there and idles. I read somewhere that the TPS plays a role in deciding if the TCC locks or not. Is that true?

 

A code 23 is a MAT low temp indicated. If your TCC isnt locking up, thats probably a VSS problem. That would throw a code 24. Are you counting SES flashes to get your codes or using a code reader. Make sure you are counting the flashes correctly(if doing it that way). Your only code might be the VSS code and not the MAT code since the codes are 1 digit apart and your TCC isnt locking up.

 

I used the paperclip method. It's definately code 23, I done it several times to make sure. The exhaust does stink, so I'm assuming it may be running a little rich. I just changed the plugs too, and all of the old ones really didn't look too bad. It sure has me puzzled.

FWIW, I did jump the two terminals to force the TCC to lock up, it still didn't work. The two problems may not even be connected, I just don't know. I'm actually leaning toward that problem being the solenoid inside the tranny.

 

Here's the diagnosing procedure for code 23. Hope this helps.

 

I notice it says..

"A code 23 will set if: No VSS, vehicle not moving"

Does that mean if my VSS is bad that it could still throw code 23?

 

I think that in test description 1, those events need to happen before it throws code 23. I dont think it means that your vss is bad. I would start doing the electrical test from the procedure.

 

OBD I is not a specfic system. it may throw a code and the problem may be some where else.

what is your idle like? steady or rough?

any other drivability problems?