After rebuilding transmission there is an odd fault

Hi,

What fault code was retrieved? The idea that it is downshifting could be related to a speed sensor or even a kick-down servo switch at the front of the transaxle. I say that because it is downshifting on you at odd times.

Let me know as much as you can. Also, let me know if you have a live data scan tool, the fault code found, and I need the correct engine size. According to my manual, it came with a 2.4L SOHC or a 2.4L DOHC. See pic below.

I will watch for your reply.

Take care,

Joe

See pic below.

Brian,

If it is going into limp mode (stuck in a specific gear), there really should be codes that are related.

If you presently have the car at home, try to retrieve codes yourself and let me know what you find. Because of the model year, this vehicle has an OBD1 system that doesn't require a scanner to retrieve codes. All that you need is a very basic voltmeter or multimeter that can check continuity.

Take a look through this link that explains in detail how it's done. Let me know if you are comfortable doing this.

https://www.2carpros.com/articles/mitsubishi-trouble-code-definitions-and-retrieval-procedure-for-odb1-system

Also, I attached a copy of the wiring schematic for the transmission. I highlighted the wires that are related to the transaxle solenoid valves. Note where they all go to. Each one is controlled by the transaxle control module located under the dash in the vehicle.

The chances of two solenoids failing this quickly are low. I suspect there is either a wiring issue between the solenoids and the control module that is being temporarily fixed when work is done. After a short time, the connection is lost.

Of course, that is a theory at this point. However, before I would replace more parts, I would wiggle wires, disconnect and reconnect harnesses and inspect them, and see if it makes things work again for a period of time.
I
Let me know. If that has been done, then it's time to start checking wiring for faults. If one exists, it is likely in the transmission. The solenoid valves are attached to the valve body. See pic 3 below.

Let me know if you are able to get codes or if there is anything I can do to help. Also, let me know if the valve body was replaced during the overhaul.

Take care,

Joe

See pics below: Note: I had to cut the wiring schematic in half to make it readable. However, I did overlap the two pics and highlight the wiring involved.

Hi,

That sounds like a plan. With the cost of used vehicles being up 46%, we need to keep the older ones going. This is certainly one worth saving.

I look forward to hearing what is found. However, if I don't hear from you for several days, I hope you have a great New Year!

Take care of yourself.

Joe