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1998 Mitsubishi Transmission Issue

I have a 1998 Mitsubishi Galant, 4cyl., 165, 000 miles. Without previous symptoms, one day the transmission developed a delay of 5 to 30-seconds before it would engage in reverse. The fluid was clean and I have been using the Mitsubishi brand that they recommend. So I replaced the original transmission with a used one. But the reverse delay continued, even with a different transmission. So I removed the used transmission and rebuilt the original one. The problem STILL remained. Since then, the valve body has been replaced and the speed sensor has been replaced. I cannot figure out why there is a delay when putting it into reverse. I ran out of solutions. I did notice one day that when I first start the car, and the engine is at 1000 RPM’s or more, the reverse wouldn’t engage. Then, as the RPM’s dropped to about 200 RPM’s, the reverse would engage. I thought maybe this would be a clue. I would love to know if anyone else had this problem and found a solution.

Sounds like something electrical, ie the computer. If I am not wrong, your car has a separate computer for the transmission. Is having the codes read an option? I think this is a dealer only thing or needs a more advance code reader that the regular OBD II readers. I would swap the ECU out from the junkyard and see.

“as the RPM’s dropped to about 200 RPM’s, the reverse would engage”

Really?
I seriously doubt that the engine would still be running after dropping below ~600 RPMs.

Anyway, galant’s suggestion is worthy of consideration.

Sorry, the “200 RPM’s” statement was a typo. When the engine is cold it runs at about 1000 RPM’s or more. Then it drops to about 600 RPM’s, and that’s about the time the transmission will finally engage in reverse. I’m thinking “galant” is correct about the computer issue. Some weeks ago I called the service manager at the Mitsubishi dealer to explain my problem. He said he would have to take the transmission apart and that would cost me thousands of dollars…even after I explained I had already replaced and then rebuilt the original transmission. I have the read the codes and nothing came up. But now I’m wondering if a more advanced code reader is needed. I DO suspect a computer problem. I don’t know if my trans has a separate computer, but I will look into it. Thanks for the feedback.

I think you need specialized help for this. I expect even a dealership won’t have the right person for a 1998 model. Yuu need a good independent transmission shop. The best one in town. Are you consulting with a mechanic that specializes only in transmission diagnosis & repair? The best local shops for transmission usually only do transmissions, and nothing else. And some transmission shops only do certain brands. Ideally you’d like one of these that does Mitsubishi.

Ask the mechanic you use for most problems for a transmission shop recommendation. It may be this is something simple to fix, but you need the right person to help you. Good luck.

If you still are chasing this problem, I would monitor the line pressure when this happens. If the line pressure is low and pops up when Reverse finally engages, I would check the line pressure in Drive and Low and see if they are correct or acting similarily.

I notice you have a Pressure Control Solenoid that should be ‘OFF’ and closed during Reverse. If the PCS were leaking or always ''ON", I would expect it to affect Reverse as well as the forward gears. If the PCS solenoid is “ON” continously, I would look for a ground in the wiring to the Transmission Control Module or a bad TCM.

It looks like you had a source for a used transmission so you might have a source for the TCM. It might be cost effective to try a replacement TCM. At the same time check the line to the PCS for a short to ground.

Hope this helps. Please post back when you find the solution for this problem.

Thank you Researcher and GeorgeSanJose. I will look into the the PCS and the TCM. Good advice. I am consulting with a really good independent transmission specialist. I really appreciate the help people are giving me. I will eventually get this figured out. Thanks all.

The line pressure is fine. The PCS is new. Today I had the Transmission ECU replaced with a recycled one. The symptoms still remain. All gears work fine except Reverse is delayed. Sometimes a few seconds, sometimes up to a minute. It seems worse when the temperature outside is cold.

When you find the solution to this problem, please get back to us.

I will definitely post here if (when) I find a solution to this problem.

Well…after a complete transmission rebuild, a replacement valve body, a replacement transmission control module and then, as a last resort, had thicker Ford gaskets put in to replace the ones that came with the transmission rebuild kit…my 1998 Mitsubishi Galant ES still delays when put into reverse. It’s hard to detect a pattern, but it does seem that when it sits overnight it is more likely to go into reverse immediately. But, when the engine is warm, the delay engaging into reverse can be anywhere from seconds to minutes. I’ve spent a lot of money on this problem and I officially GIVE UP!