: 2007 DTS - ABS not working at low speed, scare the crap out of me



laserray
12-30-10, 01:15 PM
Hi my 1st post. I have come here for answers and idea's before.

I bought my 2007 used in 2008.
I have had brake problems with the car ever since I owned it.
Crash the front due it, with in 6 months of owning it. I wasn't absolutely sure until this week when I could reproduce the problem over and over.
This week during a snow storm I went to work. I drove to the end of my street.
I was going 20 mile or under. Went to stop way ahead of the stop sign. I slid 25-35 feet onto the on comming roadway. Later that day I was so upset I decided to try it on the same road. Same result slide for along time. I think i hear/feel the abs but it doesn't feel/sound like my GMC truck. When I pump the brakes, the car stops quickly.
It has been to the dealership many, many times. We even road tested it. They made me use the abs brakes on dry road to prove it works.
I sent in today, same result, no abs light, and the "computer" doesn't say a thing. They road test and it works.

Two things I must have from a car, it must stop, and it must go.
This one doesn't stop.

I could have kill myself or somebody else, the other day, and it would have been my fault. If i can't find this I have to sell the car to some poor soul. Other then that the car has beem fine, except for the heated windsheild wipers, and losy door stop.

Tomko
12-30-10, 03:08 PM
ABS will only prevent the wheels from locking. It will not give your tires grip where there is none.

Here are a couple of questions that may help you reason through your experience:

What kind of tires are you driving on?

How many miles are on these tires?

Have you checked their tread depth?

When did you last check your tire pressure?

What is your level of experience driving in the snow?

laserray
12-30-10, 04:34 PM
OK, I'll play.
Been through all of this.
The tires are very expensive michlen tire, brand new.
Exprience in the snow, 52 years old up north, think i can't drive in snow?
My GM truck with abs brakes, WORKS.
Same conditions.

The tires lock, the car slides, slides, slides.....
You pump the brakes the car stops 6 feet not 35 feet.

yea the dealership is treating me the same way.
If I had an accident they would be saying it was me.

Sorry if i seem a bit upset, but at least 2 years, 6 times at dealership.
Today they call me, same thing, of course at 54,000 miles they want to do pads, no problem.

Here is when the failure happens, it's cold, the road is wet, simple 25mph stop.
I can do it over and over. My truck stops in 6 feet.
Of course today the roads were clean, so they can't test under my conditions.

These devices are suppose to be fail safe, or at least warn you.

If anybody has any idea, that would be great.
I check google can't find any problems about GM ABS systems at all, except for one truck model.
Same problem, low speed, doesn't work, doesn't even stop.
My wheels are locked.

laserray
12-31-10, 11:11 AM
Called GM to file a complaint.
I was very impressed with their phone support.
"Why didn't the dealership road test under same conditions?"
"I don't know".....
They even called the dealership, case started.

billdaman
12-31-10, 12:45 PM
I have been through this with my GMC Envoy, and the mountain that I live on, coming down the hill at low speed, 5 - 7 mph on snow and the ABS functions and pulses and the pedal pressure drops (again this is a slow speed thing) And I slide enough down the hill whith out any means to stop to where it scares the living crap out of me. Previous owner had 2 master cylinders and an ABS module replaced on this same vehicle, yet this still occured. My tires appeared to be good, I would never have thought they could have been the root cause of this incident.

In my opinion, there is nothing, I repeat nothing wrong with your vehicle. It is functioning as designed (even if you are NOT happy with its design) Get a new set of tires immediately.

After this scare I replaced my tires with a 900$ set of Michelins and it has NOT occured again. That was 2 years ago. However, these tires have some miles on them now and although and are still well within legal limits, and have 15,000 left on them in "Summer weather", but they are no longer sufficent for the Northeast winter. They still do their job, but just barely. They will need to be replaced before next winter. But make no mistake about it , if I put new tires on this truck TODAY. It would stop like new on snow, ICE, whatever.

This is a fact of physics and is a pure measure of the coefficent of friction between the tire material and the surface area of that tire, its depth of tread and its contact with the road surface and or what ever the properties of the materials (snow, ice, water, oil etc.) built up on that road surface may be. The response algorithm of the ABS module and pump to the imputs received is what it is, and as owners we cant change that.

Bottom line: Replace the tires. End of story!

ffrog
12-31-10, 01:49 PM
The ABS brakes should not lock your wheels, but cause them to pulsate. But you already know that.

I don’t think that it is your tires causing the problem, you said they were new. You have demonstrated this by driving your truck at the same location without any problems. Last winter I had marginal tires (since replaced) on my GM SUV and they stopped the vehicle on ice without a problem – ABS brakes are great even with bad tires.

I would continue to follow up with GM, it sounds that there is definitely something wrong with the ABS.

LOL

billdaman
12-31-10, 04:20 PM
Hi my 1st post. I have come here for answers and idea's before.
This week during a snow storm I went to work. I drove to the end of my street.
I was going 20 mile or under. Went to stop way ahead of the stop sign. I slid 25-35 feet onto the on comming roadway.

It has been to the dealership many, many times. We even road tested it. They made me use the abs brakes on dry road to prove it works.

I sent in today, same result, no abs light, and the "computer" doesn't say a thing. They road test and it works.
.


Snowstorm causes issue...low coefficent of friction, ABS pump appears to be functioning, so why blame ABS?

Wheels are LOCKED at over 5 - 7 mph on what??? ice or snow. You say the ABS activates on dry pavement yet the wheels stay locked continously on snow or ice. If you were moving at a speed over 5-7 mph, and IF ABS activated and your wheels were to stay locked that would throw a code because under those conditions the fault would be related to either the control module, wheel sensors or pump and uner those circumstances the ABS tell tale would be illuminated long after you completed your stop. I know this because I have seen the test performed in GM assebly plants at Dynamic vehicle test hundreds of times


The ABS brakes should not lock your wheels, but cause them to pulsate. ; ABS brakes are great even with bad tires.

it sounds that there is definitely something wrong with the ABS.

LOL

That sounds like A fundamental misunderstanding of how ABS works to say that wheels should never lock up with ABS. LOL

Sorry I missed the part on the new tires. I would look at the other parts of the braking system for the root cause.

hazcaddy
12-31-10, 06:07 PM
You say you have new and expensive Michelins - what kind? They can be new All Season tires and not be worth a damn in winter conditions. You need winter tires at this time of year (unless you live south of I-10).

Lev Blekher
01-02-11, 01:37 AM
So to clarify when you turn the car on does the ABS light come on and turn off? Does it flash or stay on during driving? Do you have Stabilitrak and if so, under panic stops does the triangle light flash on the display? As far as braking, do you hear a loud sound like a whine and does the pedal pulsate, or what happens as far as the feel and sound?

laserray
01-03-11, 10:41 AM
So to clarify when you turn the car on does the ABS light come on and turn off? Does it flash or stay on during driving? Do you have Stabilitrak and if so, under panic stops does the triangle light flash on the display? As far as braking, do you hear a loud sound like a whine and does the pedal pulsate, or what happens as far as the feel and sound?

There is no ABS warning light, and no bad codes given.
This is what has the dealer stumped.
The only time I ever seen the triangle light is during take off, when the wheels slip.

I do not hear the ABS whine, and only feel a slight pulse. Not the rapid pulse I am use to on the truck.

it appears I will have to wait for a bad snowy day again, and force my dealer to road test the car.

It's is NOT a tire problem, or a driver problem.
If I pump the brakes the car stops just fine. (6ft vs 35ft)
My freinds and I think is a problem of low speed, low velocity braking combine with the low slip coeff.

Now that I know a solution, I feel a little better. (Just pump the brakes)
We have become too complacent with our technology.
The ABS is not working correctly and the computer doesn't report it.

rjm
01-03-11, 12:00 PM
You aren't crazy! I've experienced this in some of my previous DeVilles, usually occurred at speeds less than 10mph. Haven't had to deal with bad weather in my '06 or '08, finally wised up and purchased the proverbial "bad weather car."

After much discussion, it was decided that since the car was traveling at such a slow speed, the computer thought the car was fully stopped, thus no need for ABS intervention. You would think that after all these years, GM would've reprogrammed the CPU somehow to compensate. When Stabilitrak was updated several years ago, it included texture detection so the system could distinguish between snow, ice, gravel, sand, etc. So why can't the system determine that the vehicle is still moving and engage ABS???

Superjim
01-03-11, 12:32 PM
The next time it rains...(we very seldom get ice or snow)...I will check mine at low speed on a slick, worn asphalt road.
Some of them darn things are almost as slick as ice when they are wet. :) :)

I will report back what it does.

Texas Jim

laserray
01-03-11, 12:37 PM
You aren't crazy! I've experienced this in some of my previous DeVilles, usually occurred at speeds less than 10mph. Haven't had to deal with bad weather in my '06 or '08, finally wised up and purchased the proverbial "bad weather car."

After much discussion, it was decided that since the car was traveling at such a slow speed, the computer thought the car was fully stopped, thus no need for ABS intervention. You would think that after all these years, GM would've reprogrammed the CPU somehow to compensate. When Stabilitrak was updated several years ago, it included texture detection so the system could distinguish between snow, ice, gravel, sand, etc. So why can't the system determine that the vehicle is still moving and engage ABS???
Well that's refreshing, someone who believes me.
At 1st I thought I was crazy or the car was too big for the tires.
But sliding 35 feet slowly heading for the oncomming street gave me lots of time to think.
Now that I can repeat the event, I have take a mechannic for a "little ride".

Many years ago I taught myself how to drive in the snow by driving around the snow covered school parking lot crashing into snow banks. Pumping the brakes became natural.
When ABS came out, I found pumping the brakes really screwed up the ABS.
I handed over that function to the car's computer.
Well you can't trust the computer to be fail safe.
I wonder how many people got into these situations.
"It's your tires, it's the weather, it's the driver, cause the computer doesn't say anything."

The next problem is ... can they fix it?
A car that can't stop is useless. And Scarey!!!
I really don't want to sell it, but if this is normal, somebody else can have it.

BTW I do have my snow car (93 GMC Yukon), but the heater had failed so I needed to drive my baby.

rjm
01-03-11, 01:42 PM
Frustrating isn't it????

Even though its been 25 years, I can still remember some of the "with ABS you have to relearn braking" lectures from service personnel.

Over time, I've learned to adapt. If its a panic stop, I stomp the brake pedal and hold on tight, but if its slow and/or controlled I brake the "old-fashioned" way (ignoring the ABS completely).

This is one reason why I wish service departments would just admit that this is the way the car is designed, and I'm speaking of all makes/models not just Cadillac. Case in point, I'm part of a very large and very close family, and talk always turns to cars when we're all together. Being the car nut in the family, I'm constantly amazed at some of the stories I hear regarding problems experienced and the resulting solutions (or lack thereof) from the service departments. Is it too difficult to say..."Mr. S all Beta Gammas operate in that manner" or "The car is performing within specifications/the way its designed." I'd still be frustrated (sometimes downright angry), but not nearly so as being treated as though I'm an idiot who was born/began driving just that morning.

laserray
01-03-11, 02:14 PM
Frustrating isn't it????

Even though its been 25 years, I can still remember some of the "with ABS you have to relearn braking" lectures from service personnel.

Over time, I've learned to adapt. If its a panic stop, I stomp the brake pedal and hold on tight, but if its slow and/or controlled I brake the "old-fashioned" way (ignoring the ABS completely).

This is one reason why I wish service departments would just admit that this is the way the car is designed, and I'm speaking of all makes/models not just Cadillac. Case in point, I'm part of a very large and very close family, and talk always turns to cars when we're all together. Being the car nut in the family, I'm constantly amazed at some of the stories I hear regarding problems experienced and the resulting solutions (or lack thereof) from the service departments. Is it too difficult to say..."Mr. S all Beta Gammas operate in that manner" or "The car is performing within specifications/the way its designed." I'd still be frustrated (sometimes downright angry), but not nearly so as being treated as though I'm an idiot who was born/began driving just that morning.

Yes it is......
Well admitting "thats how it works" opens up some interesting problems.

My other cars, including a GMC truck doesn't behave in this way.
It would be nice if they told me something, this clueless is very frustrating.

That's what they did with the door stop. "The door's too heavy for the designed door stop. End of story"
When your wondering were all your business went, then you'll worry about good service. Not likely.

rmink53787
01-03-11, 02:14 PM
Sounds as if GM is on it - after you bypassed the Dealer :P

My 2002 ABS lights came on after Rotating the tires last Dec. I replaced a Wheel Bearing hub buyt that didnt fix the ABS, I am experienced enough to pump my brakes in a skid anyway but I have checked all

ffrog
01-03-11, 02:16 PM
You say you have new and expensive Michelins - what kind? They can be new All Season tires and not be worth a damn in winter conditions. You need winter tires at this time of year (unless you live south of I-10).

I live well north of I-10 (Philadelphia, PA area) and I use All-Season tires without any problems. We just finished up with a snow storm so I went on a side street and at slow speed on ice, the ABS worked as expected. I often visit Vermont and Minnesota this time of year and have never had problems with All-Season tires.

LASERRAY please read my earlier reply I never thought for a second that you are crazy. As I mentioned in that reply you should definitely follow up with the dealer as IMO there is something wrong with your braking system. Given time they will find the problem you have ruled out tires and driver as being the problem. LOL and keep us posted.

rmink53787
01-03-11, 02:18 PM
sorry PC cting up.

anyways, anyone have a checklist on what I should checkout for my ABS System? I have done Engines and Tranny's and usual engine maintenance all my life but never messed with ABS Sytem.
Thanks

Lev Blekher
01-03-11, 06:35 PM
That is pretty weird that the fail sensor failed itself. My ABS on every car I have driven works at any speed just fine.

laserray
01-05-11, 04:11 PM
I live well north of I-10 (Philadelphia, PA area) and I use All-Season tires without any problems. We just finished up with a snow storm so I went on a side street and at slow speed on ice, the ABS worked as expected. I often visit Vermont and Minnesota this time of year and have never had problems with All-Season tires.

LASERRAY – please read my earlier reply – I never thought for a second that you are crazy. As I mentioned in that reply you should definitely follow up with the dealer as IMO there is something wrong with your braking system. Given time they will find the problem – you have ruled out tires and driver as being the problem. LOL and keep us posted.

Well I appreciate that. The dealer doesn't seem to care anymore, then doen their tests, and the computer shows I am full of it. You would think a large raging man might make them care but no. The salesman never returned my call, so he will never sell me a car again. Jenny at GM was my first contact, she was really thorough, smart, and on the ball. The case manager April was totally clueless. She hadn't even read the case before she called me. Wasting the all the work Jenny did. Basically she left at what are you going to do about it? Why don't you go to another dealer? I was hoping for a little better treatment buying a Cadillac, but it's always the same. The push you until you exploded, then they start doing something. I haven't gotten the GM area service managers name yet.
I have to wait until a really bad snow day, go in, demand they road test the car, then rip their hearts out.
You can't just calmly state the facts and get anybody to respond. I shouldn't say that, there has got to be a good dealer service department somewhere. They did do a good job on the brake job, but anybody can do a brake job.

I know at least one poster here, thought my complaint was funny, and posted the sliding cars.
Those cars were on ice covered with snow. The ABS unit would have been screaming, and he is right it won't do a thing in those conditions. However that was about the speed I was going.
I am talking about fresh snow no ice. Plus pumping your brakes, STOPS, the car.
I agree with the statement "the computer thinks your car is stopped"

disney327
01-12-11, 01:59 AM
laserray, My 2007 DTS does the exact same thing you described. It scared the crap out of me too. I just got the car a couple of months ago so it's my first winter driving with it. I have new tires, no codes or lights come on. The car just continues to slide and slide. I am not even going fast under 15mph. If I pump the brakes and the abs does not kick in, then I stop fine like normal. As soon as the abs kicks in look out because here I come. Something is wrong with the abs. I did notice that when the abs kicks in the brake pedal goes CRAZY my whole leg bounces up and down. I even banged my knee on the steering wheel. My car is out of warranty so I don't want to take it the dealer and get the run around. They are just going to charge me a fortune to look at it and say its fine pay up, have a good day. If you find out what is wrong with yours can you please let me know.

laserray
01-13-11, 06:17 PM
laserray, My 2007 DTS does the exact same thing you described. It scared the crap out of me too. I just got the car a couple of months ago so it's my first winter driving with it. I have new tires, no codes or lights come on. The car just continues to slide and slide. I am not even going fast under 15mph. If I pump the brakes and the abs does not kick in, then I stop fine like normal. As soon as the abs kicks in look out because here I come. Something is wrong with the abs. I did notice that when the abs kicks in the brake pedal goes CRAZY my whole leg bounces up and down. I even banged my knee on the steering wheel. My car is out of warranty so I don't want to take it the dealer and get the run around. They are just going to charge me a fortune to look at it and say its fine pay up, have a good day. If you find out what is wrong with yours can you please let me know.

Ahhh.... the story unfolds.
yes I will. I have to wait for the correct day to take it in.
Then I'm going to file a complaint NHTSA.
ABS systems are suppose to warn you when they don't work.
This is why the dealer can't find the problem. They are relying on the computer to tell them a sensor is bad.
My truck was running today, thank God, I hit an ice patch at low speed, and the ABS buzzed, and worked correctly. My caddy would have been out of control, unless I pumped the brakes.


If you try it on dry pavement is works ok?

billdaman
01-13-11, 09:13 PM
Ahhh.... the story unfolds.
yes I will. I have to wait for the correct day to take it in.
Then I'm going to file a complaint NHTSA.
ABS systems are suppose to warn you when they don't work.
This is why the dealer can't find the problem. They are relying on the computer to tell them a sensor is bad.
My truck was running today, thank God, I hit an ice patch at low speed, and the ABS buzzed, and worked correctly. My caddy would have been out of control, unless I pumped the brakes.


If you try it on dry pavement is works ok?

TIRES. Get rid of M+S Michelins or whatever else you are running and put SNOWS on and WATCH HOW GOOD IT STOPS. I drove my DTS in a blizzard last week for several hours and slid like I was on ice every time I went to stop on light snow...BUT THERE IS NOTHING WRONG WITH THE ABS...Its TIRES. Go ahead waste your time with NHTSA, you wont get anywhere.. Hey ask this these owners about ABS ..
Please get an understanding of how the system works!


http://www.youtube.com/watch?v=8hemAjudq4g

billdaman
01-13-11, 09:27 PM
www.youtube.com/watch?v=8hemAjudq4g

laserray
01-14-11, 10:42 AM
I understand how the system works.
Don't be so quick to assume we don't know if the ABS is working or not.
This isn't my 1st car with and without ABS.
I know how to drive in snow. I don't have this problem with other cars.

It's bad enough you are so insulting. The mechanics are just as clueless.
Somebody is going to get hurt not being prepared for what is happening.
Why can't you accept the ABS is NOT working? As you are sliding the pedal should be buzzing, no?
As I told you my truck works just fine.
So how can you conclude it's an operator fault without at least trying to road test the car yourself under simular situation? Is that too much to ask, on a safety issue?

Explain how pumping the brakes makes the car stop? Explain that that? Tires? Shez, sure that will make you slide less. yes snow tires make driving in snow, much more manageable. I am talking about sliding and what ABS is suppose to do for you. If you are sliding it should at least turn on.
This problem started to show up on wet roads as well. It was just too obvious on snow covered roads.
As i said what really upsets me is the dealer treats me, as you do. I am clueless.
Don't test it, just jack in the computer. Hey computer? Are you broken? No? Sir, nothing is wrong cause the computer said so.
We shall see.

ffrog
01-14-11, 11:14 AM
BILLDAMAN, I have Michelins All season tires (NOT WINTER) on my DTS. I live in the NE and never had problems driving or stopping in snow or ice. At a slow speed my ABS kicks in as it should.

Off topic, it is hard to believe that a person would jump out of their sliding car in the middle of the road. Also in the video someone was hanging out of the passenger side. I guess there are more stupid people then I realized.

Hang in there LASERRAY in time the problems with your ABS will surface. Have you considered taking the car to an independent brake specialiast. The way you describe it, it does not sound like your tires.

billdaman
01-14-11, 10:40 PM
I understand how the system works.
Don't be so quick to assume we don't know if the ABS is working or not.
This isn't my 1st car with and without ABS.
I know how to drive in snow. I don't have this problem with other cars.

It's bad enough you are so insulting. The mechanics are just as clueless.
.

Sorry I am not insulting you , I have the same problem as you describe. Now I am having a new set of tires put on my vehicle tomorrow, and it will improve dramatically. You have said that your ABS works on dry roads, but not on snow. Therefore your vehicles braking system is reacting to the radical differences in the coefficient of friction of the road surface between snow/ice and dry pavement.

The only thing contacting that road surface in either case is your Tires. If your tires make no hard contact at all with the road surface then they will skid on the surface until some contact is made with a surface that provides friction. At that point the vehicle stops. That is how you described it.

I am replacing my tires tomorrow for the 3exact problem as you describe. I will do a test on a road close to my home covered with snow and report the before and after results. Sorry if I came off as hostile.

regarding your comment of years of driving experience, I panicked 2 years ago when my pedal sunk to the floor and the abs did NOT work on my Envoy when driving at slow speed down my hill. I have nearly as many years driving experience as you have. However I had NEVER experienced that problem. Took a mechanics advice and stopped thinking about the ABS and bought a set of real deep Snow rated all season tires. The problem disappeared. Not ABS. That was and is my experience