Hi my name is Joe and I'm a new member. I'm hoping you can help me.
I have a 1992 stealth auto 139K it's a new purchase and although use has been limited shes was shifting thru all gears.
The trans fluid looks and smells new. Now when in drive she begins and ends in 2nd gear. Manually 1st and 2nd gear work when in gear using console.
The only problem with the car has been battery drain The battery was switched out a few times .
One time while it was running I was attempting to tighten positive terminal the steel open ended wrench hit the body and arched for a sec I heard the engine stumble and slow down a sec then returned to normal. I didn't drive the car since. My buddy took it out and said while in drive she was only in second gear. I didn't feel a shift either.I disconnected the battery for a half hour in a attempt to reset computers.
I disconnected the battery again cleaned what electronic external transmission connections I could find with electronic contact cleaner. After another half hour my friend drove the car with no change. The engine is running fine with no rough idle or stumble smooth as silk. I do not have the fuse box cover under dash so can you please tell me which fuse is trans related . My friend did probe with tester and said they all cameback ok. I would like to double check though. Is the trans in safety mode?
I have tried to research and thought about removing battery negative again and then the connections from ECU and TCU reconnectiong then hook battery back up. I'm afraid of trans shop hoping for a self cure if possible. I'm a novice but can get some help if I have direction.
Thanks!

 

Did this problem start after you arced the battery? If so, there is a very good chance you shorted out the TCU.
Yes, you are in "limp mode." It could either be a TCU malfunction or a an internal problem with the tranny its self.

 

Thanks for the reply. The problem did occur after I arced the battery. Today I disconnected the battery cleaned the TCU and ECU connections reconnected the battery and unfortunately there was no change. I spoke to a friend and he has a shop that would do a trans rebuild for 700.00 - 800.00 that's all well and good. I'm concerned that this is electronic. The dealer wants 85.00 to do the scan. My buddy has a used car lot and he hates Mitsu trans and sends out Mitsubishi trans for work the shop he uses always rebuilds them and not once has it come down to changing the TCU. Whether it's a Mitsubishi product or Chysler slash Dodge not just the Stealth any shared model.
that scares me. I would rather pay $155.00 for a salvage TCU, is salvage a good idea it come with a 45 day guarantee. Then 700-800 for a rebuild. I found a TCU same year online at a yard is there anything else I would have to do to a TCU after install? I'm here on this site for a reason no one I comes across seems to be overflowing with knowledge regarding this issue and it can become an expensive mistake. I'm guessing a dealer scan will pinpoint any trans problem? Is there a chance that it is mechanical if the ECU was spared? If the jolt was strong enough to do damage would both be hit?

Thanks Again! I really appreciate it.

Joe

 

If this was not a problem until you arced the battery, I would almost guarantee it to be an electrical problem. When you pull the TCU and open it up, you will be looking for leaky capacitors. Mitsu used poor quality capacitors in their auto electronics and they will start to leak, causing odd electrical gremlins to arise. I don't believe this is what is wrong with your considering you did give the system a good jolt when you arced it. If you can get a TCU for $155, that is a decent deal, but it will be prone to leaky caps in the future. If you get yours rebuilt, the rebuild shop will be able to tell you what exactly was wrong with the TCU.

To get to the TCU, you have to remove the side panels on the console. The TCU is on the floorboard, near the firewall. Some of the bolts are a pain to get too, but you shouldn't have too much trouble removing it. Unhook the battery terminals before you remove any of the harness'...you don't want to burn anything else up.

 

Good news it was a bad TCU board. I put in a rebuilt board and the transmission shifts great! I lucked out in that an older gentleman I met who repaired my daughters bose radio has worked on Mitsu TCU boards before.
Without a schematic he rebuilt mine for $85.00 and bingo it works perfectly. There was visible damage on the board close to the input plugs.He is very knowlegeable and fixed it in a couple of hours. I would appreciate it if anyone has a link to the TCU and ECU computer schematics.If I get the schematics I can put his info up on the forum obviously without the schematics he cannot test. I think he was very fair compared to sites I've seen and even cheaper then most salvage boards. If I get the schematics he would be willing to take on more work. I hope this would benefit everyone. I can tell you he takes his work seriously and is very dilligent and honest.
Thanks to TheStealth for his forum replies and guidance.