I had a similar thing happen to my VW Jetta. It turned out to be a bad rear wheel speed sensor. Actually not the sensor but the magnetic ring that's built into the rear hub. Initially I replaced the sensor, no help. After replacing the hub all was well once again.
If you're asking what the speed sensor has to do with the tire pressure and the traction control systems, the computer uses data from the speed sensor to determine what's going on with the wheels for the TCS and the TPMS.
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