Automatic Tranny downshift problem...

[kristmen]

Question for anyone who knows about automatic's. My girlfriends DSM has an automatic in it. Lately she has noticed it wont downshift when going up hills or underload. I took it for a drive and she it right.

All the gears work fine, I mean it shifts up threw the gears fine, no hard pulling or anything, runs good other then it dont want to downshift when needed which sorta makes the car bog out. She has to manually downshift it.

If you really get on the gas, like slam it to the floor sometimes it will downshift.

Does anyone know how one might fix this problem?

 

[transdude]

I think that you may need to check the tps, it may be going bad or it may need to be adjusted. It could also be related to other engine management sensors (maf, etc.)

 

[mtxtsi]

i had the same problem in my car, the computer shorted out some how, whein the computer was replaced that car drove just like it did before it went bad.

 

[kristmen]

I assume you mean the trans computer. The TCU..

The auto trans has silonoids in it and if you dont keep the trans fluid clean one or more of them will clog or stick sending a voltage spike to the TCU in turn shorting it out.

Its VERY important for drivers of automatic DSM's to keep the tranny serviced.

I flushed the tranny, changed filter and fluid 2 day ago, didnt help.

 

[RuBiCaNT5X]

I am having THE SAME problem. It's not as bad on the load where I slam on the gas and it won't downshift, it does but I gotta hit the pedal somewhat... I gotta call Mitsubishi and find out how much a TPS is gonna be.. Any ideas...