2002 Sequoia Sport Utility SR5

[zipsick]

I recently purchased a 2002 Sequoia Sport Utility SR5 for my Grandson. I had it thoroughly inspected by a Good Mechanical Shop. It passed with flying colors with the only suggestion being to get the brake fluid flushed.
I checked the CARFAX and it too looked really good. It had been maintained by a Toyota Dealership with regular servicing upkeep. It is a beautiful car with the works in accessories. Immaculate interior. At a Reasonable Price.
Too good to be true.
It ran fine at first but after a couple weeks we started having a problem with it vibrating really hard. The light with the Car with the swirling lines under it comes on in the dashboard. Indicating that the Traction Control System or the Electronic Stability Control (ESC) is active. This happens while driving on normal well paved roads. The only way to stop the vibration is to pull over to the side of the road. Then you can drive again with no problems for days but it happens again every week. The vibration is so strong it makes for a dangerous driving situation.
Does anyone have any idea what the problem could be? If you have had these symptoms in your Sequoia and had it diagnosed and fixed please share your experience with me. What was it? I am going to take it to a Mechanic for a diagnoses. I am worried when I take it in and the Mechanic drives it, it won’t act up and vibrate hard and have the light come on. Then the mechanic won’t get to see the problem happening for himself to understand what’s happening with it. I wonder if the Mechanic will charge me an outrageous price diagnosing the problem?
When I was having the Sequoia’s brake fluid flushed I had the Mechanic check its Main Computer. No problems were found there. They checked it and it passed with no errors.
I was thinking maybe I need to take it to a Toyota Dealer because it’s going to be a very hard to diagnose problem and they might have some Specialty diagnostic tools. I don’t know if I should take it to my regular mechanic who fees will be cheaper than a Dealer but may not be able to find the problem and I end up paying for a lot of diagnosing with no answer and I will end up having to take it to the Dealer anyway?
Help me out here please.
Why would a 2002 Sequoia SR5 2 wheel Dive start to vibrate very badly and have the light with the Car and swirling lines under it come on when there are no driving conditions to justify it?
What is wrong with my Sequoia????

 

[Twowong4words]

The ABS/traction control(TCS) systems use magnetic sensors in each wheel that sit just above a rotating tone ring. The tone ring turns and the sensor detects a high/low voltage condition which the system counts and uses that to determine the wheel speed of each tire. If the sensor goes bad, the wiring is damaged, tone ring is damaged or the magnet gets enough metal particles attached to it(bad wheel bearing), it can cause the system to see that as a wheel not turning or turning at different speed then the other wheels which it then assumes is the wheel has either loss traction or the wheel has locked up. The system then opens a brake fluid dump valves or applies braking force(inside the ABS module in engine bay) to the affected wheel to stop the spinning or release the brake pressure to get the tire to get traction again.

What it sounds like to me is you have a bad wheel speed sensor/tone ring or wiring issue that is telling your ABS module to take action to correct the issue. A shop scanner can get live data for each wheel speed sensor and tell a technician which wheel it thinks is not turning or spinning and from there you would have to pull the sensor, test it, check the wheel bearing and look inside the sensor hole while turning the tire to inspect the tone ring for damage. It can also be a bad ABS/TCS module or other issue not specifically related to the TCS/ABS system but since that light is coming on, that is where i would start.

It is also possible with traction systems that if you have miss matched tire sizes, rim sizes or extreme variations in tire wear that the system could see this as a wheel speed issue. This is something you can do without taking it to a shop, just check tire sizes and rims are the same. I've seen people put the spare on one side which didnt match the rest of the wheels or significantly bigger tires on the front or rear axle or rotate miss matched tires to one side vs the other.

There is also a process called Zero point calibration you can do via sticking a paper clip in the DLC port under the dash in a specific pattern but it is probably easier to let the technician do this with the scanner in most cases. But it is not very likely in my experience that this would resolve your issue.

I have not personally experience your issue in the shop or on my own Sequoia but if someone brought me one with the suggested symptoms you have described, that is where i would start.

 

[zipsick]

Thank you so much for all your information! You were very thorough and detailed with your thoughts. I will defiantly check the tires also. You have helped me very much!!!!! This was very nice of you to take the time. Really appreciate it!!