02 Bonneville le 143k+ miles, lost the overdrive & cruise @ the same time. I travel for wok so I ended up putting another tranny in w/ only 80k. On occasion, it will work, there'* a noticable hard clunk into gear & I can tell that everything shifts - just a little hard, as long as I don't turn the car off I could drive the car all day. Now the car won't shift out of 2nd gear,(@ first I was unplugging the top elect. plug on the tranny, sprayed it w/ contact cleaner & that "seemed" to do the trick, now not so much) I've swapped out computers (had it reprogrammed) & it'* still not commanding 3rd. 1810 came up as a code- has to do with the positioning switch connected to the linkage that the cable connects to. do i pull the this tranny out & fix that or just get the old one fixed (4th gear clutch)

Check the fuse marked Misc engine/cruise, or may say OBD Sounds like that fuse went out. I believe your car has one box under the hood, and another under the rear seat.

With the replacement unit installed, I regained cruise & 4th- when it shifts out of 2nd. I thought that fuse may be suspect, checked it- swapped it w/ another fuse, still n/a. i had the orginal unit scanned, & I got the impression that the 4th gear "spline clutch" or cable may have stripped out? was quoted just as much as the cost of a replacement...through "a friend of a friend". (<300$)

What causes the 2nd- 3rd shift not to command 3rd?

Do I spend another 150 on a flush & filter?

Pull this trans out, get the 4th gear issue with the orig fixed & re install?

on a thin branch, replace the mass air filter sensor "just cause"???

The car is in GREAT cond, no rust, I've only owned it a little over a year (the tags JUST came due) - besides a few radio/heater control light out....

Don't quote me on this, but if I recall, the cruise and tc lockup only happens if certain engine parameters are met. A misfire may prevent lockup, a P00XX may prevent lockup. Even with other issues, it may prevent the cruise from working also. Kinda like a built in safety system.

P1810 possibilities.
TFP valve position switch signal circuit is open or grounded

TFP valve position switch circuit shorted to another signal

TFP valve position switch is damaged or has failed

PCM has failed

Are you sure you have the correct P code? You may have a faulty shift linkage sensor.