Multiple simultaneous failures

[rrosen]

Driving my 2008 GMC Yukon XL Denali when all of a sudden, ABS light comes on along with stabilitrak failure and traction control failure warnings appearing. Previously service suspension warning had come on then gone away. I'm guessing an electrical failure because I can't believe everything failed at once. Any clues where I should start looking first?

 

[swathdiver]

Welcome to the forum Robert. It's usually one item failing that's interconnected with all of those features. Sometimes it's the failure of AFM, other times a brake switch under the dash or wheel speed sensor on the front hub or rear axle. Check connections and wiring at each tire for a visual but you really need an advanced scan tool that can read ABS codes to tell you exactly what's wrong.

 

[kbuskill]

Even a cylinder misfire can cause all those warnings. When the ECM detects a misfire it disables TC, ABS, and Stabilitrac to take those out of the equation to see if they are causing the problem since those systems have the ability to cut timing to the engine when they sense a wheel free spinning.

 

[broken08]

You are wasting your time doing anything other than going to the dealer and having them do a scan tool. Not a standard scan tool, has to be GMC. I have, on multiple occasions, gotten them to come read codes without dropping it off. Say you are in a hurry and the code comes and goes and you want to get a reading while the code is present and you are worried since it disappears sometimes. That will get you some ideas.
For me, the things on this complete POS truck that have caused that light in two years of ownership: every time it left my family and I stranded on the road from randomly dying with unknown still cause (super common on these), Cam phaser, cam sensor, oil pump, electronic shock failure, rear airbag failure, bad battery, failed alternator, oh, and what's that last thing...oh, a spun cam bearing requiring a NEW BLOCK! I will, never, ever, ever, buy a chevy or GMC product again.

 

[thompsoj22]

You are wasting your time doing anything other than going to the dealer and having them do a scan tool. Not a standard scan tool, has to be GMC. I have, on multiple occasions, gotten them to come read codes without dropping it off. Say you are in a hurry and the code comes and goes and you want to get a reading while the code is present and you are worried since it disappears sometimes. That will get you some ideas.
For me, the things on this complete POS truck that have caused that light in two years of ownership: every time it left my family and I stranded on the road from randomly dying with unknown still cause (super common on these), Cam phaser, cam sensor, oil pump, electronic shock failure, rear airbag failure, bad battery, failed alternator, oh, and what's that last thing...oh, a spun cam bearing requiring a NEW BLOCK! I will, never, ever, ever, buy a chevy or GMC product again.

Next time your driving your GMC, count the number of other GMC trucks you see and wonder if those owners are getting hosed in the same manner? I wonder if the phenomenon that you have experienced could actually be explained by "factory reps in the know". in other words, was your vehicle part of a production run with a bad employee in the engine section and they are aware of it? or a run of bad alternators, batteries, shocks? The factory will never disclose their inside knowledge.

 

[rrosen]

Well, my code reader now says left front ABS sensor bad. Looks pretty hard to get to so headed to the shop I guess.

 

[swathdiver]

Well, my code reader now says left front ABS sensor bad. Looks pretty hard to get to so headed to the shop I guess.

The ABS sensor is part of the hub. The whole thing has to be changed. But it could also be unplugged or a cut wire! Timken is the best and only one you should use.

 

[iamdub]

Even a cheap one-way scan tool can point you to the root cause of such an event. When codes are set, the PCM makes "screenshots" of what all the sensors are reading at that moment. If you take a look at the screenshot(s), you may find an open and/or low voltage on a particular circuit of a system that is part of the ABS and StabiliTrak systems such as the TPS, TAC, or as you found, the ABS. Could be a faulty sensor or loose connection in a harness, including a ground.

 

[HiHoeSilver]

Well, my code reader now says left front ABS sensor bad. Looks pretty hard to get to so headed to the shop I guess.

2-3 hour driveway job with $100 part and basic tools. Don't go get hosed. Agree with @swathdiver, only Timken.

 

[Doubeleive]

that abs sensor is super easy and you can verify if it is just the sensor or not by simply switching it with the other side and see if the code follows it or not, if it does not follow the sensor then you most likely need a hub, chances of it being a bad connection elsewhere are pretty slim.
turn the wheel, take off the one bolt that holds the sensor on the hub, unclip the harness connectors and swap it with the other wheel, should take you like 10 minutes max