My left rear motor went bad also. I managed to take aparts the motor enclosure since I am an electronics guy so I wanted to see what happened. But the board looked pristine. Some people had suggested water leakes in and shorts it out but this was still clean and dry. Nothing was burned up that I could see under magnification. It is CAN controlled so not really serviceable. I got a "new" one from a junk yard for 60.00. Be careful of the EBay replacement ones. There were some non CAN types sold in Canada and other places. They will say it fits but it doesn't. Unless you are in Canada I suppose...

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra