How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Toyota Service Your Own Question
Toyota Service
Toyota Service, Toyota Expert
Category: Toyota
Satisfied Customers: 4608
Experience:  30+ Yrs of auto experience, Award Winning Svc. Manager; Just Answer Customer's Choice Award Winner
14892859
Type Your Toyota Question Here...
Toyota Service is online now
A new question is answered every 9 seconds

Taking off from a dead stop only, the trac control kicks on,

Customer Question

taking off from a dead stop only, the trac control kicks on, NO slippage from tires. Happens even if I just idle off from a stop. No other time does it engage without tire slipping or aggressive maneuvering. If I 'roll' through a stop sign and punch it, no issues. Again, only from a dead stop.
JA: How old are the tires? And have they been a problem in the past?
Customer: 2 years, no issues, in trying to solve I had them rotated, lower ball joints replaced, aligned. No luck
JA: What is the model/year of your Toyota?
Customer: 2001 Sequoia
JA: Are you fixing your Sequoia yourself? What have you tried so far?
Customer: yes
JA: Anything else you want the mechanic to know before I connect you?
Customer: replaced both upstream o2 sensors\
Submitted: 2 months ago.
Category: Toyota
Expert:  Toyota Service replied 2 months ago.

Hello. Welcome to Just Answer. Please allow me to assist you. The problem you describe is not unlike several similar instances we have encountered in the shop. The most common issue was a fault in the device called the 'tone ring'. The tone ring is the unit that the wheel speed sensor uses to measure the RPM of each wheel, and sends this data to the ABS/traction control computer. If the one wheel data stream does not match the other three on dead stop acceleration, the computer assumes wheels spin, and activates the traction control. Unfortunately, this cannot be determined without the use of the Toyota scan tool, which is capable of displaying the RPM data stream of all 4 tires. A scan of the real-time readout on dead stop acceleration should reveal the corner of the car that needs to be taken apart and visually inspected. I would not be surprised to see a cracked tone ring. Note that this conditon will not cause a fault code. Please confirm you have received my input on your request. Thanks

Customer: replied 2 months ago.
Thank you. If it was a tone ring, why would it only occur from a dead stop acceleration?
Expert:  Toyota Service replied 2 months ago.

You are welcome. To answer your question, it is because at a dead stop, all four wheels are at zero rpm. The issue is on acceleration. One of the wheels is not sending the same RPM to the computer as the other three wheels are. At higher RPM, the potential defect on the tone ring is not as critical.

Expert:  Toyota Service replied 2 months ago.

Thanks for choosing Just Answer. It was a pleasure to assist you. I trust my input is satisfactory and meets your expectations. A positive rating for my assistance on your request would be greatly appreciated; thanks again and have a great day

Related Toyota Questions