Hey i have a eco auto transmission. yr is unknown 03-05? any way its part of our swap and we have it doing local drives(waiting to get inspected) and ive solved most of the codes it trew. now im down to the last two codes i cant seem to get rid of. the codes are scaned and show as follows

P1810 TFP Valve Position Switch Circuit
P1815 Transmission Range Switch-Start In Wrong Range

can any one break down and explain what they both relate to and how to go about repaining them. All ive come to is its in the trans(duh). Im no trans expert so im at a stand still. id like to get this fixed so we can get the car going. I do know it had a bad case but that codes were up before. Now could it be something stored? like possibly from the old motor? The car is a 00 cav auto prior 2.4l owner lol. now that was removed and dropped a 05 eco in. the prior owner said that the car didnt wanna start and her mechanice said needed a new motor so hence we just eco swapped.Planned to anyway. But could this be issue stored in the cars original system somewhere?.
The motor and trans and comp are all from 3 diff cars.So if this is stored somewheres in the car idk since we never had it running with old motor. just with the new on.Now i know when i put around in the neighborhood she seems fine. shifts into park n gear ok. The trans and converter were completely drained before install by the yard so. we applied a total of 12 qrts so far and thats what the service said from dry to full. still havent pulled that flow plug to comfirm it full but. anyideas please help. any info please ask ill respond quickly. Thanks.

Wayne, I was digging through my service manuals again last night and thought of something else I forgot to include in the email I sent to Jessy regarding all of this...

The P1810 can be caused by a faulty fluid pressure switch (or the whole module, which I think in the Eco trans consists of 5 circuits...3 open and 2 closed...and the fluid pressure switch)...or like I wrote in the email, a bad connection on the terminals or the connector can cause a faulty signal...

Now let's assume everything in the module is working correctly...you had a leak in the trans case, which could have been enough to cause the TFP circuit to read low enough pressure/fluid level to throw the code...so I'm thinking two things:
1. The trans case leak that was on the car caused the code...
2. If you remember, when you checked for a new trans case at the yard, the one on the blue sunfire was also cracked....well that just happens to be the same sunfire the I pulled the computer from for you, so maybe on some chance that car had a cracked case before it was wrecked and it was a stored code from then (though I think it's not very likely...much more likely that the cracked case on ReRun was the issue)

Now also, I mention about the connector (I think it's a 16 pin in our case?) that connects the trans harness to the rest of the wiring harness...I mentioned how it's prone to road dirt/salt/etc build up and can effect a proper connection...well the more I read about it, if that is the case that the connector is filthy, it may cause one or more of the TFP circuits to not function and will cause the code because the computer thinks there is a low fluid level, due to receiving faulty info from the module.
And of course, in the case of the connector being dirty (or hell, not securely connected), well that can also account for the P1815 code.


I would first check/clean the harness connector, then check the terminals by the case and make sure you have a good ground connection, that way, if that doesn't start to fix it, you can at least rule out a electrical issue before looking for a mechanical one.

I'll let you know if I think of anything else.

solved issue. checked/cleaned and secured all connections again. checked fluid level, etc turn out to be a failure on the computers end. tried in a another j with no know issues and still triggered the codes. put good comp in the car and all was fine.