Blue Angel

I need some help from the forum...

A good friend of mine just had a very bad day. He was getting onto the highway in his newly imported to Canada '01 Z06. Just after getting into the left lane, with the car in 4th gear travelling only about 115 km/h (~70 MPH), the car VIOLENTLY spun out of control for no apparent reason. The car crossed over three lanes of traffic without hitting any other cars and went into the ditch backwards, cartweeled through 200 feet of fence and dirt and came to a stop on its roof. He crawled out through the shattered rear window and walked away with only a stiff neck and some cuts and bruises.

The car had previously experienced all the "symptoms" of a faulty EBCM, including DIC failure instructions for the Active Handling, ABS and Cruise Control as well as slight "pulling" side to side from individual random brake caliper application.

I'm trying to "survey" the experiences others have had with EBCM failures, and whether any serious accidents have been caused.

As it stands tonight, the car is in a towing yard shop in pieces, every body panel destroyed, all glass broken, and the chassis in an unknown state.

Any help with this will be greatly appreciated!

Herringchoker

I think if you read through all the posts the thread "List of owners with EBCM issues" you will find some who think they or someone they know had a accident because of this.

Blue Angel

Checked out that thread, seems to be an awful lot of C5 owners driving around in cars that could kill them without notice... my buddy counts himself lucky to be alive, let alone walking and talking. His car is ABSOLUTELY TRASHED, every panel is EFFED, ALL glass broken, wheels, tires flat, etc. etc. etc. People at the scene of the accident couldn't believe he was able to get out of the damn car, or be alive at all after watching it flip through the air numerous times...

Has any progress been made with contacting the NHTSA? I own an'02 Z that I'm now worried about driving, and the car has performed flawlessly since I bought it two years ago... knock on wood.

With this many people OBVIOUSLY at risk of a serious or fatal accident I feel something should be done.

qwkz06

First of all why was your friend continuing to drive his car with DIC for ABS/AH/CC? Sounds like he should have used some common sense and serviced his car.
Secondly, It is much much more likely that the crash was caused by your friends driving and not anything to do with the car. The vette ABS/AH/CC is not significantly different in any meaningful way than the Electronic Stablity Control (ESC)that NHTSA is advocating strongly for ALL cars and light trucks. In fact recently the only vehicles that the Insurance Institute for Highway Safety (IIHS) gave their highest rating to all had stability control and they would not give the highest rating to any vehicle without it. Chances are very very strong your friends poor driving caused his accident just as many others and is now trying to blame the car.
If you go to NHTSA's website you will see consumer complaints about every high volume car from brakes to acceleration to steering etc. People now a days tend to blame anyone or anything else for their own conduct. Most of the complaints, even those that lead to NHTSA inquiries do not pan out and do not lead to any recall.
JMHO

Blue Angel

Why don't you ask the same of every other 'Vette owner with the same issues? I'm sure there are many thousands of people in the same situation and don't realize how dangerous this condition is. Did you read the post that was linked to above? This is not something "made up", this is a real problem and has affected many people. It is not my "speculation", it is fact. What I'm trying to find out is, of all the problems people have had, how many have had accidents caused by the EBCM functioning improperly.

This guy was NOT EVEN AWARE of the severity of this issue until I brought him onto this forum after tha accident last night and started searching. He's not an active forum member like I am, and therefore had heard little of this problem.

Also, the EBCM had already been replaced once in this car leading him to believe the problem may have been something else. I say that replacing a defective part with a defective part is not the solution to the problem...


Did you read what I said initially? He was traveling aprox. 70 MPH in FOURTH gear, going straight ahead in the left lane. He also had two witnesses (who were almost hit) stay at the scene and verify his story to the Police; they both estimated his speed about the same as he did and told the Police that he was not doing anything wrong. The guy who was in the next lane said he was "amazed" at how the car instantaneously lost control "for no apparent reason". The car has a set of B&B PRT mufflers on it, so if he was on the gas hard or doing something stupid the other drivers would DEFINITELY have heard him.

Also, this guy is no stranger to high HP RWD cars. He's 30 years old and has owned a '67 Chevelle since he was a teenager. The car has a ~550 hp 468 BB Chev under the hood. He also owns a '98 SS Camaro, and has owned two older F-Bodies strictly as WINTER cars. This guy knows how to drive, and the way he describes what happened was similar to the time his Chevelle had a wheel bearing seize in the rearend; the car INSTANTLY spun out of control for no apparent reason, and it happened so quickly that he had no time to correct. He's corrected for thousands of oversteer conditions before, and in cars far more of a handful than the Z.

All true statements, but this does not mean that not all of these cases are legit. Large companies make decisions on recalls based on how much it will cost to fix ALL the cars VS. how much it will cost to pay all the lawsuits. These decisions are made all the time by car companies, airplane manufacturers, etc. It's sickening, for sure, but true.

All I'm trying to do here is gather information. If you feel the need to hijack people's threads and question the people involved, don't do it here.

If you have something constructive to add to the conversation please do, I'm all ears. If not, and you've not even educated yourself on the topic, please keep your OPINIONS to yourself.

Wicked Weasel

rgtkst

the black box in the vehicle may be very usefull for him in this case. the same black box so many flame as a intrusion of privacy!!! so... the driver is saying it was as if one of the front wheels locked up and sent it into a spin?? anybody have a chance to inspect the car yet to see if any of the brakes are locked up??? or rotors broke. i had a chain from snow chains wrap around my front suspension while cruising down the free way and it locked the pass. front wheel up tighter than heck. any chance he picked something up off the road?? a real inspection will show if there was a mechanical failure or not. there was a thread going about the "black box" that records the last 5 seconds prior to an accident just a few days ago. there are many threads about that as a matter of fact. the last one talked about who has the $2500.00 tool to read it also. might be the best way to find out what realy happened. hope your friend is ok!!!!! sounds like a hell of a ride to go thru. tell him WE ALL here say "hope your doing OK"


i would be looking at the steering system before the computer causeing this. a broken or come loose linkaege would do the same thing. just a thought!!

JeepTJ

Another reason I am glad I don’t have Active Handling.
Hope your friend is OK.

georgec114

Well....Now that was helpful...

qwkz06

I'm sorry you don't like other scenarios than your friends description and one of those scenarios involve personal responsibility. If there is a malfunction light on your dash a reasonable person addresses it. I assume your friend can read. There is a basic source for information...The owners manual.

The fact that there are people driving around with their AH/TC or other trouble codes illuminating the dash does not make it smart or right. If you have an air bag light on your dash do you think it is still going to work properly? That is why their are "idiot" lights on the dash!

70 in 4th gear sure would seem to indicate he is not just cruising along. Maybe he is not getting on it but he is not just driving along.

Notwithstanding there are plenty of explanations including...sorry to say....the driver just not paying attention and then doing something improper...The fact that he thinks he is a good driver and has driven many more powerful cars actually is just as supportive of someone who just doesn't want to admit they screwed up as someone who knows what they are doing and just couldn't have had such an accident.....

If there was a failure in the system a download of the SDM/EBCM should provide some good insight into what happened. If a failure as your friend NOW claims occured it can be confirmed or disproven.

Have him report it to NHTSA and see if they will investigate. If there are enough people who report the condition they will follow up. And by the way, NHTSA is not GM. Their decision whether or not to order a recall is not based on lawsuits.

I assume your friend was insured. Make sure he tells his carrier of his claims. Maybe they will look into it as well.


Where did he get the car? What does he know of the history? Run a carfax? Replacing EBCMs is necessary every now and then but usually something else has happened to cause it. What other problems has he had?

I know I sound very suspicious/jaded but it is amazing how many people wreck their cars/bikes etc and then try to blame to car or bike. "My brakes failed" "My steering locked" "The car accelerated on its own", "my seat belt didn't work", "the air bag didn't depoy in the accident..it must have deployed later" etc. Ultimately most are shown to be impossible or that they could not have occured as claimed.

Good luck to your friend and I am glad he wasn't hurt badly. By the way, we sure would like to hear what the results are..and by that I mean an official report not just your friend claiming GM agreed the car was at fault or alternatively some information on whether your friend ultimately just can't prove his story.

Was that constructive enough? I sure hope so. I assumed you were not just looking for people to somehow come up with support for your friends story but rather, as your post starts with needing some help from the forum..

Lancer033

when the TC system has a fault, it just turns off. In that situation, the car drives fine, except the AH won't save your butt when you mess up. I drove mine for several months without the AH, you just have to remember you don't have ABS, other than that it drives normal.

RichieRichZ06

All of the items in bold are very good arguments. The first thing that I read in the original post is the 70 MPH in fourth gear statement. I agree that nobody just leisurely drives down the freeway at 3,000 or more RPM without having the intent of screwing around.

I rend to agree that if the car has a MIL on the DIC, then take it in and have it looked at soon. Allthough, the worst thing that could happen is that the ABS will not function, but not that the car will brake all on it's own.

I have worked for a dealer for 6 years and have never heard of an instance (especially one that has been proved) of a car applying the brakes on it's own. We have replaced a ton of the EBCM/BPMV's in dozens of cars, but I have never heard of this.

There have been many accidents towed into our body shop where the person involved stated that the car violently changed direction, braked or accelerated without any input from them, but after stating that the EDR could be removed and downloaded, their tune changes very quickly. This is especially true when people realize they could be in trouble for lying about what really happened.

I also am glad that your buddy was not injured very badly, but I really do not think it was the cars fault. If you do, then I guess that is what friends are for, but most rational thinking people will not agree with the way this accident allegedly went down.

Blue Angel

Much better than your first post... thank you.

His car would drive normal with the entire system shut off, no DIC warnings or anything, cruise worked normally. As soon as he enabled the TC or AH, even in Competitive Mode, the car would start acting up.

I went to the accident site today... holy crap. His car hit the ditch going backwards, then flipped and tumbled for over 200 feet! It took out about 150 feet of fence and guardrail before coming to a stop, and this was all after he skid across three lanes... the tire marks were still quite visible on the hwy.

There's a road that parallels the 401 directly to the South, and I found parts of the car across the street on the front lawn of one of the local businesses. What an eye opener.

Once again, still looking for any information regarding accidents caused by faulty EBCM modules.

Z16 #1669

"He's corrected for thousands of oversteer conditions before, and in cars far more of a handful than the Z."

I'm not sure what this means. That's a lot of times to be correcting for oversteer isn't it?? Or do I missunderstand??

RichieRichZ06

Well after reading the riddiculous claims of the ABS acting on it's own I decided to call our GM field technician. After reading the thread to him, he laughed for a minute and then provided a document ID from General Motors describing the description and opperation of the entire ABS system. He also stated that he has "burned" more than a few people who attempted to claim the same thing happened. Most of the accusations came from a person who was driving a high powered car in less than perfect conditions and was too proud to admit that the just plain f**cked up. He stated that the system relies on a brake input from the driver to activate the system and there is no way for the system to activate brake pressure on it's own. The only pressure that can act upon the lines is that from the driver pressing his foot on the pedal and sending fluid down the lines. Basically the guy driving the car had to have put his foot on the brakes to make the system activate. In other words, he was not just cruising down the freeway at 70 MPH. If the DIC was showing a message that the system had a fault, the worst case scenerio is that the ABS did not work and the driver slid and lost control. So here is the copied description and oppperation from the GM service manual. Note that the description of the system states that it CAN NOT increase pressure to any wheel, it can only re-apply the pressure as to what was already put there by the pedal going down. OOPS! I think that the guy might want to read this before going to court or he may be in trouble for purgury. Hey man you asked for info and you got some info. It may have not been the answer you were looking for, but it sure is usefull info at that

Antilock Brake System (document ID# 671064)
When wheel slip is detected during a brake application, the ABS enters antilock mode. During antilock braking, hydraulic pressure in the individual wheel circuits is controlled to prevent any wheel from slipping. A separate hydraulic line and specific solenoid valves are provided for each wheel. The ABS can decrease, hold, or increase hydraulic pressure to each wheel brake. The ABS cannot, however, increase hydraulic pressure above the amount which is transmitted by the master cylinder during braking.

During antilock braking, a series of rapid pulsations is felt in the brake pedal. These pulsations are caused by the rapid changes in position of the individual solenoid valves as the EBCM responds to wheel speed sensor inputs and attempts to prevent wheel slip. These pedal pulsations are present only during antilock braking and stop when normal braking is resumed or when the vehicle comes to a stop. A ticking or popping noise may also be heard as the solenoid valves cycle rapidly. During antilock braking on dry pavement, intermittent chirping noises may be heard as the tires approach slipping. These noises and pedal pulsations are considered normal during antilock operation.

Vehicles equipped with ABS may be stopped by applying normal force to the brake pedal. Brake pedal operation during normal braking is no different than that of previous non-ABS systems. Maintaining a constant force on the brake pedal provides the shortest stopping distance while maintaining vehicle stability.

Pressure Hold
The EBCM closes the inlet valve and keeps the outlet valve closed in order to isolate the system when wheel slip occurs. This holds the pressure steady on the brake so that the hydraulic pressure does not increase or decrease.

Pressure Decrease
The EBCM decreases the pressure to individual wheels during a deceleration when wheel slip occurs. The inlet valve is closed and the outlet valve is opened. The excess fluid is stored in the accumulator until the return pump can return the fluid to the master cylinder.

Blue Angel

He was just merging onto the highway and was accelerating in 4th gear. He was in the left lane, still in 4th, when all hell broke loose. In 4th gear at 70 MPH a stock Z is not exactly making traction breaking power to the wheels... and two witnesses stopped and confirmed they saw the whole thing take place and he was not doing anything unusual or unsafe looking.

Random individual brake caliper activation is WELL DOCUMENTED on this and other forums... read this post as suggested early on in this thread:

http://forums.corvetteforum.com/show...th+EBCM+issues

Read posts #38, #92, #104, #117, #198, #220 (good one!), and I'm sure there will be more to come... Locking right front wheel at 107 MPH (Post #220) states this problem pretty clearly I think.

What is the cost to have this done, and does it only record this info if the airbags go off? His airbags did not deploy. He has no problem getting this info out of the black box, if anything he feels it may back up his story! When he first told me what happened he was not blaming the car, he simply said "I wrote the car off..." Not until after we got searching for EBCM info did he think that this may have been the cause.

Believe me when I say I was skeptical of this when I first heard the news too... this guy bugged me about leaving my car in Competitive Mode when driving, and clearly stated that he wouldn't bother with electronic "nannies" to "help" him drive if/when he ever got his hands on a Z. My first thoughts after the news sunk in was, " Oh boy... I wonder what he was doing..."

I also knew at the time he was usually driving with the TC/AH turned OFF because this was the only way to get the car to stop acting up. He tells me he doesn't remember turning it off before he went out last night.

Seeing this normally very confident driver so totally humbled and completely unable to make sense of what happened changed my tune towards this incident pretty damn quick. As I say, he was not blaming the car initially, and still isn't 100% sure the car was at fault, but the mounting evidence we're uncovering in these forums is strongly suggesting that the car could have been the cause of the crash.

Let me be perfectly clear, once again... I'm gathering information, I'M NOT BLAMING THE CAR, just trying to understand the failures seen by the public at large and whether or not the car could have been the problem.

He imported the car less than a week ago. It had a 10 day trip permit on it, he hadn't had time to get the car fully checked out.

Blue Angel

Drive an '87 IROC for a winter car and count how many times a DAY you need to dial in a little opposite lock to keep her straight!

vetteman9368

thats all well and good the ABS cannot apply pressure that's wonderful, hoowever the active handling can and will apply brake pressure. How else would it work? devine intervention?

Blue Angel

You JUST beat me to it!

RichieRichZ06, have you ever even triggered the AH in your car??? I personally have had my FOOT TO THE FLOOR on the ACCELERATOR, the car snapping sideways, and before I can even react the car has already closed the throttle partially and applied braking pressure to one or more brake calipers to straighten the car out.

This is a fantastic system when it works properly, and I drive with it on Competitive Mode all the time. Maybe you should hit the books and learn something about the cars you're spending so much time working and giving advice on!

Now can I PLEASE get back to the business of trying to learn something here???

gpracer1

I think you guys are mixing ABS with AH/TC. They are not the same.

ABS is antilock braking system. It has to do with only you pressing the brake pedal and any wheel locking up. It pulses the pressure to the locked wheel to allow it to turn and not skid. This system is totally independant of the others.

Traction control closes the throttle when the wheels spin.

Active Handling can apply the brakes to any wheel at any time that the computer deems necessary to keep the car going in the intended direction based on many different inputs. It just happens that it uses the abs sensors in the wheels to measure whether any of the wheels are spinning or sliding.
Lets say you turn left really hard and the front end slides....The car knows how many G's you are pulling and knows what the steering angle is and should be, and knows which wheel is spinning faster than the others. So it decides to drag the left rear wheel brakes to make you turn better. Kinda like turning brakes on a sandrail. Etc, etc.

As far as this accident, who knows. He is lucky to be alive whether it was his fault or the cars fault.