420A 420a auto transmission won't move car

[Kingcron32]

I have a 1998 Eclipse GS auto that I replaced the transmission in. I got codes P1784 and P0700. The first says "gear R incorrect ratio" and I'm assuming the P0700 is related to the first.

The car starts no problem, but when I select a gear, nothing happens, except a small rev acting like it's going into gear, but the car won't move at all. I've looked on here for answers, and it looks like it could be the TCM or the solenoid pack.

Has anyone run into this, and have a solution? Thanks

 

[Dsm1996Eclipse]

The reason why it seems like it goes into gear and is not moving at all is because the the TCM is reading that the L or R gear pressure switch is open or closed at the wrong time and it puts the car in a limp mode. First thing you should do is check the trans fluid level, low fluid is usually the main cause for the P1784 code but if the fluid level is high it could also throw the code. Check all connectors to the solenoids see if there are any that are damaged, there could be a open or short. Doing the trans service might do the trick as well, the filter might look okay but it could be plugged.

 

[Kingcron32]

The reason why it seems like it goes into gear and is not moving at all is because the the Tcm is reading that the L or R gear pressure switch is open or closed at the wrong time and it puts the car in a limp mode. First thing you should do is check the trans fluid level, low fluid is usually the main cause for the P1784 code but if the fluid level is high it could also throw the code. Check all connectors to the solenoids see if there are any that are damaged, there could be a open or short. Doing the trans service might do the trick as well, the filter might look okay but it could be plugged.

The fluid level is good. It was a little high, but I corrected it. I have a new filter and fluid in the transmission. Are you talking about the wires in the big plug with the bolt on top? Also, I noticed that the front wheels will still spin when the transmission is supposed to be in "park". Could this be due to the torque converter not being seated fully, and not engaging? This is the first transmission I've ever done, so I'm trying to learn as I go.

 

[Dsm1996Eclipse]

The fluid level is good. It was a little high, but I corrected it. I have a new filter and fluid in the transmission. Are you talking about the wires in the big plug with the bolt on top? Also, I noticed that the front wheels will still spin when the transmission is supposed to be in "park". Could this be due to the torque converter not being seated fully, and not engaging? This is the first transmission I've ever done, so I'm trying to learn as I go.

So yeah the big plug on top of the trans, you could do simple power and ground tests to the solenoids to see if you are actually getting inputs might need another person to move the gear selector through the gears. Another quick question what type of fluid did you use? Using the wrong fluid could get the solenoids stuck they are super anal about using ATF +4. It sounds like the torque converter isn't disengaging if it is still spining while it is in park, it could also be a issue with the transmission itself, which some of the solnoids and pressure switches aren't serviceable. You could also hook a scan tool that could look at the trans data to see if the tcm is correctly communicating with the ecu, by seeing if the correct gear is being displayed on the scan tool.

 

[Kingcron32]

So yeah the big plug on top of the trans, you could do simple power and ground tests to the solenoids to see if you are actually getting inputs might need another person to move the gear selector through the gears. Another quick question what type of fluid did you use? Using the wrong fluid could get the solenoids stuck they are super anal about using ATF +4. It sounds like the torque converter isn't disengaging if it is still spining while it is in park, it could also be a issue with the transmission itself, which some of the solnoids and pressure switches aren't serviceable. You could also hook a scan tool that could look at the trans data to see if the tcm is correctly communicating with the ecu, by seeing if the correct gear is being displayed on the scan tool.

Valvoline full synthetic. (The bottle says good for Mitsubishi). I have the Zurich zr-bt1 scanner. I was running the transmission scan and that's when it gave me those codes I said earlier. Then I ran it again a few days later and it wouldn't give me any. So could that mean it's trying to communicate, but maybe it's got a bad connection somewhere? I don't think the scanner I have will allow me to do anymore. Do you think the torque converter could be bad?

 

[Dsm1996Eclipse]

Yeah that should be good for the fluid, If the code is intermittent it could be that the L and R gear solenoid is sticking, what you could do is find a schematic of the the solenoid connectors and see if you are getting consistent inputs. The torque converter could be faulty but the codes that are being thrown are pointing more to the sloenoids being stuck. Usually with a bad torque converter you would be experience and issue mostly trying to could in reverse.