VSC, ABS and low tire pressure lights on 2004 Sienna cancel cruise control

We recently traded in our 2005 Sienna for a 2004 Sienna with lower mileage and way more features. Though we were dismayed to find that the runflat tires and non-standard 18" wheels will likely cost us dearly over the long run, that is not our immediate problem.



Within days of driving our “new” van home, the VSC, ABS (steady) and low tire pressure (blinking) lights began coming on intermittently and without apparent cause. If we turn off the engine and restart, they usually go off, but come on again relatively quickly. Each time, if the “laser” cruise control is in use, it immediately cancels and displays “error 3”. If no cruise control is on, it is possible to turn on the “normal” cruise control, but if “laser” is attempted first, neither one will work.



We have taken the van back to the Mazda dealer three times, where they have replaced the brake sensor relay twice and recalibrated something, but each time we pick it up, within twenty miles the lights are back on. They sent it to the Toyota dealer across the street on two of those occasions, and they were no more successful in repairing it.



Could it have something to do with the 18" wheels?

Sounds like that could be the cause. The tire pressure lights probably mean the aftermarket rims did not have sensors put in, or they are not calibrated for the different pressure in a runflat on larger rims. What is VSC, Vehicle Stability Control? I wonder if the TPS is enough to disable the other systems because with one or more tires “low” then the systems are designed to disable. Does any of the ones come on first? I suspect the TPS should be blinking the whole time.