# Stabilitrak/Traction Control Warnings



## NickD (Dec 10, 2011)

Some Standford professor received a grant from the government to say ABS is 14% safer on vehicles without it so congress made ABS law. Interferes with the braking of one wheel on the claim that a wheel has better stopping power if permitted to rotate than if completely locked.

Traction control is just the opposite, will apply a pulsing brake to a wheel that is slipping or turning faster than the wheel on the opposite side. On the theory by braking that wheel, the vehicle will run straighter, also kills the engine, does this all by itself. Some people swear by it, others swear at it.

Each wheel has a sensor, just a small 1/2" long permanent magnet with several layers of magnet wire on it near a toothed gear to generate these pulse, also exposed to road salt that can plug that gear or corrode the sensor. Have four of these to be concerned about.

While anyone can buy brake parts and they claim ABS does not interfere with normal braking, affordable scanners do not want to show the codes claiming they do not want to accept the liability, so it takes a very expensive scanner to read these codes. Most of them deal with the wheel sensors, either opened or shorted. When you hit the ignition switch, does a static test, namely for the power on relay and continuity for the ABS pump. When you drive about 5 mph or so, a dynamic test is done., Just checks if you are getting pulses from all four wheels.

On the Cruze, the two rear solenoid valves pulse as a cheap way to get rid of the proportioning valves. Don't need these either, because if they would make the rear caliper pistons or drum brake piston small about less than half the size, that is about 80% less area for only about 20% braking on the rear wheels. But since they are pulsing on rear disc, also need an anti-rattled added.

But this is not the only problem, controlled by a microcontroller that has code stored in flashram and requires a good power on reset. So any low voltage problems can ignite the ABS and/or the traction control. Typically too complicated for the average person. Also have to periodically replace your brake fluid because it causes gum in those really tiny solenoid valves so they won't energize, and in some cases, completely block any braking to that wheel period.

This is what happens when congress gets involved with automotive. When ABS was optional, really got a first class unit, huge modulator and a super sized ABS pump. Now, barely at 4" sized cube with a little tiny pump motor on it. Use to pulse at 10 per second, now more like one pulse per second, all vehicles are like this now.

Also a battle even if under the BB warranty, claim brakes are not covered under warranty.


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## R3DSh1ft_Cruze (Jul 25, 2016)

I talked with my brother this morning as he was heading to to work (he's a former GM mechanic) and he thinks its nothing more than a wheel speed sensor. We just recently had a spate of monsoon weather here and that loosens up a bunch of what is called tailings (leftovers from iron ore mining- the town uses it as road fill and as grit for slippery roads). It's everywhere and it can screw up the sensors. I made an appointment for the car with my tame GM dealer... see where that goes.


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## ChevyGuy (Dec 13, 2014)

Maybe, but I thought bad wheel sensors would trigger ABS warnings. 

The Stabilitrak/Traction Control warning seems to be triggered by the smallest of engine problems as well. Such as a miss.


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## NickD (Dec 10, 2011)

> and the warning lights for traction control and ABS lit up as well


Caught my eye.


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## R3DSh1ft_Cruze (Jul 25, 2016)

it was indeed a wheel speed sensor only this failure was a little more... interesting. Something failed in the hub assembly and whatever it was sheared the top of the sensor right off. Ouch. Replacing hub & sensor at 3pm today. The downside? Hub is $185, sensor $25.

*edit... there is a spacer between the cv joint, knuckle and bearing assembly... it disintegrated and destroyed the wheel bearing... the rear face of the bearing had pieces missing from it. So, a tiny spacer caused all this crap.


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