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Q: Erattic shiftingworking

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transmission replaced because of erratic shifting, now auto still shifts erratic. whats the problem?

My car has 150000 miles.
My car has an automatic transmission.

A: Erratic shifting can be caused by a number ...

Erratic shifting can be caused by a number of issues. Without knowing the specific vehicle, I can list a few potential issues. If the transmission is vacuum controlled, things like weak vacuum to the shift modulator can cause erratic shifting as can a faulty vacuum modulator itself. If the transmission is electronically controlled, the transmission control module can be faulty. You may want to return the vehicle to whomever replaced the transmission to further look into the issue.

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