Odd Downshifting Transmission

[PrairieDog]

Hi, I have a low mileage (under 63k) 1994 GT Auto (probably the 2.73 rear end) that will start dropping out of overdrive (and once out of 3rd down to 2nd) after about 15 mins. of driving on the highway, wind isn't an issue. It will continue to do this maybe every 15-20 minutes while driving until I stop the car. Bone stock car, but it only had about 620 miles put on by the prev. owner in the last 10 years. I flushed most of the fluid, replaced the filter, nothing excessive in the pan, replaced the shift solenoid, still happening. Anybody had this issue before?

 

[07GtS197]

Sounds like the mlps (neutral safety switch) to me.


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[white95]

@lwarrior1016

 

[PrairieDog]

Thanks 07Gt5197, I bought a new one on a whim. It'll go in next. I read somewhere that a failure can cause some issues. But it's always nice to hear others have the same idea. The car has never thrown a code either. Not that a OBD1 is all that diagnostic. I'll just need Spring to come around to test it out fully. Convertibles and Winter snow don't go well together.

 

[lwarrior1016]

If it still happens after the mlps replacement, it could be a speed sensor going bad. I’m not too familiar with the obd 1 diagnostic capabilities, but a good scan tool should be able to read shifter position and speed sensor output, I know my scanner can do that on obd 2 stuff.

 

[PrairieDog]

Sounds like the mlps (neutral safety switch) to me.


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That's exactly what it was. Thanks. Shifts correctly now!

 

[TheNaturalOne]

Old thread, new member, but I am having the exact same issue with my first year base S95. I can't wait for the sun to come up so I can try this. Old threads are the best. Nothing like getting your question answered from years in the past. Love these forums!