Hi guys, I have a 2003 Cavalier, with a 2.2 ecotec, auto transmission. Approx 130,000kms. I have been having some troubles recently with it. Here is what is going on:

I do have the codes:
P1810 - TFP Valve Position Switch Circuit
P1815 - Transmission Range Switch - Start In Wrong Range

Sometimes when I am driving my car will not shift into overdrive. It will stay in third. I can move the shifter from D to 3 and back and/or D to N and back. Nothing happens. Turn it off and turn it back on fixed it the first time it happened, now it doesn't anymore. Disconnected the battery and reconnected fixed it once but other times I have tried it hasn't.

Frequently if I start it up after it has sat for awhile it will shift into overdrive but then if I shut it off and restart it a coupe mins later (ie after refueling) then it won't shift into overdrive. It is extremely frustrating.

Me and my mechanic friend messed around with the gear selector and linkage and it all seems to be correct but that may be something to investigate further?

Should I replace the TFP switch? If so...how?

Also seemingly randomly my cruise won't work. If it is not shifting into OD then frequently it doesn't work but I remember it working once when I was stuck in third. I was thinking it could be the lever but it works at random times so I do not know? I feel like it is not the lever

Could these two problems be related? If so I could use any advice. Thanks

 

Hey, I am also having the similar problems with my 05 cavalier. Ive replaced the transmission output speed sensor and it did not help. LMK if you have found a solution. Thanks

 

I changed the tranny oil and filter. Then disconnected the battery. After awhile the comp seemed to learn what was what. I have found that if it does not shift into overdrive I put it in neutral from 100 km/h to 70km/h ish (coasting) then put it back in drive. Then it seems to work. Thing is if it shifts fine once it will the whole drive until you restart it. So once you coast and fix it you should be good for that entire drive. Doing this everytime it doesn't shift right seems to help it Learn how to shift properly as I rarely get the no overdrive problem anymore. Oddly enough if you unhook the battery it almost seems like you have to restart the learning process. Hope this hekps