Overdrive and shifts problems

CHRIS2100

MEMBER
1997 FORD F-150

Hi my 1997 f-150 5.4v8 has had a few weird shifting problems that are starting to get worse. My check engine light is always on. I checked the codes and there's always the same two.

P0755 - Shift Solenoid B Error
P1728 - Tran Slip Error

They come back very quickly after I clear them. For a while now my truck doesnt want to shift from first to second very easily. It revs really high in first and I have to let off the gas and then it shifts into second. It does this about 50% of the time.

The second, and more serious thing, is that quite often (say maybe 3 or 4 times a week with regular driving) my overdrive "OFF" light starts flashing on my shifter. When its doing this the truck shifts very rough. It doesnt go away until I turn off the ignition and then start it again. Then its good. Sometimes for a week and sometimes for a half hour. Is this just a sensor or is something more serious like my tourque convertor? I've asked my mechanic but he doesnt give me a straight answer so I though I'd ask rather than have him spend a few hours doing exploratory work.

Thanks for any help
Chris

2 Replies

KEN L

MASTER CERTIFIED MECHANIC
42,895 POSTS

I would start by taking care of the P0755 - Shift Solenoid B Error which sounds like you need to replace the shift solenoid B.

Here is a guide to help you see what you are in for when dropping the pan.

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

Here is a guide to help you test the solenoids

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Here are the locations (below)

Please let us know what you find. We are interested to see what it is.

Cheers, Ken

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