I have a 2000 montero sport, 4x4,aprox 125,000 miles. I will be driving along, and the trans will downshift on its own, does not matter how fast I am going. The neutral indicator and the drive indicator will flash alternately. the service engine light will come on. I can pull over and shut off the engine and start back up. It may be ok for a while after that, but will happen again sometime. also, once this happens the first time the service engine light will be on all the time. I have had it at the dealer for 6 weeks, they tried several things, but cannot find the problem. Finally gave up on them. I would really appreciate help

 

check your battery and battery cables if the alt is going it will do the same thing

 

Also, may or may not be directly related but when was the last time you changed your tranny fluid? It should be done regularly but most owners don't do it as instructed in the owners manual.

 

I have had the transmission fllushed and the fluid changed about a month or two before this started happening, I though about haveing it done again just to make sure the correct fluid was put in


I have never thought about the alt causing this, how do I find out if it is going bad?

And thanks for your replies

 

have the battery and alt load tested a bab battery cable will do the same thing

 

I mentioned that to the mechanic that has it now. He did say that he had a code for the speed sensor. He was going to change it and see what that did. He also mentioned he was getting a 3 digit code, 770. He said he did not know there were any 3 digit codes, and that he did not know what it was for

 

Mike,

That flush would be the first thing I'd check. Wrong fluid means tranny rebuild time which is $$$$$$$$$$$.

I do the flush annually and make absolutely sure they put the correct stuff in my '90 AT.

HTH

 

Take it back to the dealer and have them flush your tranny with Genuine Mitsubishi Diamond SP III fluid.

 

well, the speed sensor was changed, and I have been driving it around a little to test it out, of course the last time it took about a month before it acted up again. I need to take it on a trip to check it out. I will keep you all informed. In the mean time, thanks to all of you for your input