Same problem on toyota sienna!
http://townhall.edmunds.com/direct/view/.f0fa178/53
This is the exact problem I have.
I have 2004 AWD SIENNA. A week ago, when I started the car in a freezing morning and drove in subdivision road, the slippery light and beep came on and the break acted here and there on the wheels. At the very beginning, I thought the road was slippery. But it was not the case. There was no way my van was skidding all the time. I was only driving at 10 MPH. Then I realized the VSC was wrongly activated. Whenever I get to more than 10MPH, VSC got activated and broke the speed down to 5 MPH. I could only drive at 5MPH without getting VSC activated.
Then I realized I could not drive this van on the road. I parked it back in garage. The next day, my wife drove it out of the garage and got the same symptom. We put the van back to garage for another 3 days before I was about to call a tow truck to tow it to a dealer for examination. I tried it again. Miraculously, the problem went away.
I went to the dealer and talked to the service adviser, he said he knew nothing about the problem (recall etc.) and asked me to bring the van back for service once the problem happens again.
I have to correct the title of this thread. It was not the ABS (When break peddle pressed, break pulses when wheel blocks, no light or beep in this case) that was activated, it was VSC (slippery light and beep comes on, break activates). It was not traction control either (only light will come on, no beep). All three features are controlled by the same module.
My van appears to be working correctly now, but I dare not drive it far away from home. I know the problem is not gone. It will come back at the most inconvenient time. I do not want to be stranded in a snow storm at -30 degrees F that I can only drive at 5MPH (That is what the weather is like here in Chicago at this time of the year). I do not want to be thousand miles away from home when the problem happens again.
I read someone wrote that the dealer cleaned wheel sensors and recalibrated the system and got the problem fixed. I went under my van and inspected the 4 speed sensors (The only sensors that are exposed to the outside). I did not find visible unusual dirtiness, snow, ice etc.
I would be more than happy to get the VSC feature disabled when it false activated so that I could drive the van to the dealer instead of getting it towed, or I could drive home. VSC is just a nice to have feature, not essential to the van. I have been driving a car with no ABS, Trac control, VSC for more than 10 years. The dealer and Toyota 800 number told me there was no way I could disable VSC.
I did some reading and found there were 2 VSC related relay blocks in the fuse box under the hood. They have "VSC MSR" and "VSC Fail" printed on them. I tried to remove one of them and then both of them. The ABS and VSC light passed the start up test and went off. They come on once I drive for about 50 feet. Now the van can drive without ABS and VSC. Mission accomplished.
After I put the VSC relay blocks back and drive for about 50 feet, both ABS and VSC light went off. The ABS and VSC are back again.
I have to make a disclaimer even thought I am not claiming anything. You do whatever you do to your car/van at your risk. I am not telling you what to do. I am just sharing what I think I would do when the problem occurs.
After I found out how to disable VSC, I drove my van 200 miles away to Wisconsin Dells for 3 days. It made the round trip no problem.
I have to be cautious to see when my Sienna will fail again.
