Toyota: 2001 4 Runner/2WD, rear brakes, toyota dealer

Question
Recently had new tires put on (appx 3 weeks ago), same size as original but different brand-Michellin instead of Dunlap.  Rear brakes now occasionally screech & thunk but only when backing up.  Just recently (today) the "TRAC OFF" lite & "VCS TRAC" light have come on along with the "check engine" light.
No other problems, have keep up with regular service & maintanence, have 71,000+ miles, city driving only (Los Angeles)....What could this be?

Answer
Hello,

I think this is independent from the tyres, maybe they did not fix something in the rear axle, and something like ABS or TRC sensor broke up, have it checked by a Toyota dealer, they could read from the ECU the correct error code, and then know which is the problem.

Regards,
Jack