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Q: My car is jerking from 2nd to 3rd gear and downshifts. Will jerk a little

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After a little driving my car will jerk from 2nd to 3rd gear and downshift. It will jerk a little too. Sometimes it will smooth out on the highway and sometimes it won't do it at all. They hooked it up to the computer and got a code for P0661 but I can't seem to understand why that would affect it. My transmission was rebuilt 45000 miles ago and it's been on and off like this for a year and a half and I already performed a fluid change and filter. Any help would be greatly appreciated.

My car has 230000 miles.
My car has an automatic transmission.

A: Hi, thanks for writing in. Your car has wha...

Hi, thanks for writing in. Your car has what is called a secondary shifter valve or solenoid valve that is operated or directed by the PCM (Powertrain Control Module) which is what controls the drivetrain and transmission. Code P0661 is related to this and is what is causing the jerking between shifts. This can happen when the solenoid itself is bad or faulty or simply due to a poor connection or shorted harness. If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make or suggest any repairs as needed.

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