Traction Control Goes Bad
Love it or hate it, today’s cars have great technology, making you a safer driver. This technology can handle adverse weather conditions better than most any driver! Growing up in New Hampshire before this technology reared its ugly face, meant great driving fun in the winter.
Ripping across an ice covered lake or burning sideways into the driveway, ice and snow were always a great reason to get a car sidewards. The configuration of the road in front of my house and the driveway allowed for some great, get it out of shape driving.
Yet, even in the winter, you can come into my driveway hot enough to lose control, go over the snow bank and clean a clothes line post off like a tooth pick. In my defense, the car was facing the right direction when I came to a stop.
It wasn’t until my wife leased a Nissan Murano did I come face to face with technology! If you think getting sidewards in a front or rear wheel drive car is fun, try an all-wheel drive, it’s heaven!
It took a little work to get my hands on her car, but on that faithful day the snow was falling and I’m sighting in on the turn to my driveway. A quick twitch of the steering, a tap on the brake and a strong foot on the gas… here we go!
Face of Technology… Stupidity Control
That ugly face of technology stepped in! With a buzzing, engine RPM’s dropped, Stability Control kicked in and all of a sudden I’m driving like my grandfather!! With a shattered ego I politely parked the car. In reality, what happened was quite amazing. Stability control, in my case stupidity control.
Christine is a proud owner of a 2008 Mazda Tribute. Mazda is loaded with technology, things like Stability, Traction control, ABS and so much more.
When I heard Christine’s voice, the concern was not due to a poor cell phone connection. She explained that her car’s traction control light was flashing and her car was losing power; she could hardly go 30MPH. She went on to say the ABS light would come on and then go out. One minute the car would drive normal, then chaos would return. Christine managed to get home but refused to drive any further. Frank, Christine’s husband crawled under her car the best he could and then gave me a call. That ring on the axle is cracked and loose. That explains it all… the toner ring is broken, the car needs to be towed if the traction control cannot be disabled.
Later that day Christine’s Mazda arrived on a flat bed.
Up on a lift the cause for the problem was easily found. Yes, the toner ring was cracked and loose.
A toner ring looks like a ring with teeth. Right next to the toner ring, there is a sensor that counts the teeth as they pass by. This information is sent to the ABS, Traction Control and Stability computers. A toner ring and sensor are mounted at each wheel, the computer knows how fast each wheel is turning. Monitoring this information allows the computer to step in and take control when the driver is out of control.
How Does a Crack Invite Chaos?
Here’s the great thing about technology…it can go wrong when bad information (chaos) is involved.
So you ask, “How can a crack in a toner ring cause problems like this?”.
What do we know?
1. There is a sensor that counts the teeth on the toner ring as they pass by. The sensor doesn’t know it’s a crack it just counts.
2. The computer uses the count to determine how fast the wheel is turning.
3. With this information the computer compares all 4 wheels to each other.
When you step on the brake pedal ,the ABS computer is looking and comparing all of the sensor information. If there is a crack in the toner ring 2 different problems can occur. 1. The sensor counts the crack as 2 more teeth, which equals the wheel turning faster than the others. 2. The distance (which equals time) between the the tooth before and after the crack causes the computer to think the wheel is going slower than the others.
A cracked toner ring during braking will cause false ABS activation, most often at low vehicle speeds. This results in extended stopping distances. Not a good thing. So if you find your ABS system activating while pulling into a parking space or as you approach a stop sign, you have a problem that needs to be addressed before it becomes a bigger problem.
The Traction control computer’s job is just the opposite of the ABS computer but uses information from the same toner rings and sensors. If the traction control computer sees one wheel going faster than the other it slows that wheel down. How? First, the traction computer tells the engine computer to cut back on power. If that is not sufficient, the traction computer tells the ABS computer to apply the brakes on the wheel that is turning too fast.
Chaos & Chaos
You have the Traction computer, ABS computer and Engine computer all trying to correct a problem that does not exist! Let’s throw one more problem into the mix…A toner ring is not just cracked it is moving freely side to side. First, there’s a signal then it’s gone, oops it’s back but moving faster, no..no it’s moving slower, hey where did the signal go? One computer asking the others, are we missing a wheel?
There you have it..all of the computers are screaming at each other trying to bring Christine’s Mazda back into control.
The fix to get Christine’s Mazda back on the road was a replacement toner ring which came free with the replacement axle.
Northwood Garage… Keeping your Car Good to Go! Since 1955