Down shifts on an incline and will not shift up

1998 PLYMOUTH GRAND VOYAGER
197,000 MILES • 3.3L • V6 • 2WD • AUTOMATIC
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RAYMOND MILLER
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  • 1 POST
Periodically I will get a "service Engine Light" but the car acts normal. Checked with an OBDII code reader brings up one of two codes: P1698 or P1776.

Also, if driving on a trip and encounter a long grade where the transmission shifts down to a lower gear, the transmission will not shift back up when a level condition is regained. but, I have found if I shift the car into neutral while moving and turn the ignition off and restart the engine - then it drives normal until I pull another hill. Again, the same error codes are read on the OBDII code reader. The codes can be erased and may not return for weeks under normal driving conditions, or until the car sets for a period of time (two to three weeks), or I pull a pretty good incline where the transmission has to shift down.

Responce 1:
I changed the transmission fluid about 500 miles ago when I first experienced the problem, but no change - problem occurred again. P1776 is defined as Solenoid Switch valve In low range position. I think I obtained that definition from Google.
May 22, 2019 at 11:42 AM
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ASEMASTER6371
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Good afternoon,

How long since you changed the oil/filter in the transmission? I would start there as it could be a valve body from dirty fluid.

https://www.2carpros.com/articles/automatic-transmission-problems

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

I found the 1698 code but there is no 1776 code. Can you verify that code?

The 1698 is a serial data code for communication between the ECM and the TCM.

Roy

Roy
May 22, 2019 at 12:45 PM