1997 plymouth-where's the speed sensor control

My plymouth grand caravan is acting really funny. What's not working is the speedometer, odometer, cruise control, and trans. is acting up 2nd to 3rd and 3rd to 4th. On a engine scan at a trans shop the guy said the codes showed po500, po700, 56, 57. I talked to the trans. guy and he said trans. is shot w/o looking any further. Fluid is smooth, non-burning, with no metal shreds in it. Got another scan that showed different. We have changed both the input sensor and output sensor and there has been no change. We have the speed sensor control *hoping that's the problem. Where is the speed sensor control located and how hard is it to change? Could an over filled trans be the cause of this problem? Could just a trans filter and fluid change fix this? I'm thinking that the speed sensor control bad. PLEASE HELP!!!

P0500 Speed Sensor Circuit Error
P0700 Transmission Control Circuit Error
P0756 & 57 Shift Solenoid B Error

Not sure what you mean by "speed sensor controller". Transmission Control Module (TCM) maybe? It's on the passenger side fender wall just forward of the power steering reservoir. Got a hunch if you fix the sensor problem you'll fix it all. I take it you verified through continuity checks all the sensor wiring from the sensors to the TCM and PCM are good.

Since you have one in hand can you describe it or send a pic?

We finally decided to take it to the trans shop after looking with no luck...well, there is no "speed sensor control" on ours. Just an input and output sensor on the trans. They ran another diagnostic and told us that the TCM needs to be replaced. Said the trans. looks ok. After reading about so many others problems I'm wondering if this is the answer. I can get one from a salvage yard but I'm getting diff. info from diff. folks. The salvage yard days the dealership doesn't know what they're talking about and vice versa. Is it true that the numbers on the actual tcm I pull from my vehicle need to match exactly for it to work properly? This is what the dealer is saying. The salvage yard says it doesn't matter and that we can use any tcm from same make and model of enging. Plus, how will I know if I'm getting a good used tcm? Can it be tested? If so, how? What do you think the chance is that this is what the problem is considering what I've listed above as the problems? thanks!!

Exact part #s on TCM? Can't say for sure but, I would think they would have to be a match as the dealer says.

Here's a link talking about mismatched connectors on both the input and output speed sensors. The actual TSB references 1989 through 1998. Might talk to the dealer about it. It may or may not apply. The Chrysler TSB # is 21-06-99. http://www.jasperengines.com/pdf/41te-42le2_tb.pdf

Ok...now what...replaced the TCM and everything worked great. Transmission shifted beautifully, cruise control worked, speedometer and odometer without any problems....for about 10 minutes....then back to limp mode. Took it to have a scan run and got p0700...again. At first it was p0500, p0715, p0700. Now it's just p0700. We figured we got a bad used TCM so we traded it for another. Same thing. What could it be? The trans. shop said they checked all the wires and that everything looked fine. PLEASE HELP!!!

Did the tranny shop check for moisture in the electrical connector on the solenoid pack?

I don't know. Is that hard get to? Can you explain to me where that connector is? They said they checked all the transmisssion wiring and everything tested ok.

I don't know. Is that hard get to? Can you explain to me where that connector is? They said they checked all the transmisssion wiring and everything tested ok.

Follow the transmission cooler lines from the tranny to radiator, you should see the electrical connector just under the cooler lines off the tranny. I believe it takes a 10mm socket, short extension and 1/4 inch drive rachet to remove. This connector seems to be a trap for moisture causing eractic electrical connection, dry and apply diaelectric grease.

hope this helps