FiberglassFan

There is a lot of 'head in the sand' thinking on the subject of errant brake applications, with a LOT of people wanting to think of the car's systems as totally infallable, but the truth is that this IS in on-going problem. Way back in the day when I was looking to buy a C5, almost a decade ago, it was a problem and the reason I choose to purchase only a '97, or a '98 that did not have the active handling option. Starting in '99 there was no option, it was just standard and you lived with it. I ended up with a '98 that did not have the AH option. I would see sporatic postings on the forum about cars seeming have a brake apply all on its own, sometimes resulting in injury or loss of the car. Later, a member of a local Corvette club had an AH failure that ended up spinning the car at freeway speeds into a guardrail, tearing the entiore side off it, and nearly killing his wife. Even the simple antilock brake system has had issues...I have expereiced no less than 4 occurences where the brakes would forcable let off when I was in very low speed traffic, just creeping. In all the cases, it took the full effort of BOTH LEGS pushing as hard as I could on the brake to stop rolling and keep from hitting the car in front of me. After the 4 th time I totally disabled the anti-lock brake system and have for years driven without incident with the brakes being modulated ONLY by my foot. Electronics sysems FAIL, and electronics systems made by the cheapest bidder in some foeign nation, made from the cheapest materials, will fail more often. I have suffered failure of the anti-lock brake system, total shut down of the main engine managment computer-reqiring replaceemnt, which also lost my dyno tune, 4 -now going on 5 replacements of the climate control system. 3 turn signal wands, 7 headlight wands, and I am also currently suffering failire of the ambiant air temperature sensor, the knoock sensor and the oil pressure sensor. I can deal with things that are inconvient, or that prevent the car from running, but falires that can cause injury or death, let alone property damage, are not acceptable. Our Government has now mandated that ALL CARS sold in the USA have active handling systems, and these systems will eventually KILL hundreds if not thousands of people as they develop errorts that cause uncontrolled behaviour of the cars. The same governments have also mandtated the removal of lead from electronics, not understanding that lead free solders are not nearly as long lived and reliable as eutectic alloy lead solders. Essentially, any lead free electronics item is a time bomb of sorts, bound to fail from failure of the solder joints, far sooner than the same item made from proper lead alloy solders. There will likely be no recourse for any liability from these kinds of failures, as the reasons are systems and materials that are mandated and required by law. If you have a Corvette equipped with Active Handling, REMOVE THE FUSEs that feeds the system. It may save your life, or the life of another person.

The clip that holds the Yaw sensor is prone to failure as these cars age, allowing the sensor to swing to and fro, thusly telling the computer your car is in BIG trouble, even when in reality it is not. Our friend that suffered the colision with the guardrail after being spun at freeway speeds found the clip on this sensor had failed. It's not only swinging sensors, its bad solder joints, leading to computational errors. It is not practacle to remove the modulator from the brake lines that creates the Anti-lock brakes system and the Active handling system, but you CAN remove the power from it. It works by electric solenoids, ...and with power removed, the solenoids will not function.

Another major safety system of the C5 was already allowed a wavier by the Governement, to be totally removed, that being the steering wheel lock. If you want proof that GM has plagured our otherwise great Corvettes with **** electronics, one need look no further than the countless accidents that led to final recall where the 'well engineered' locking ystem was finally removed from the car completely.

FiberglassFan

Its wiorse than that....AH started to be an option in Corvettes in the '98 model year, and standard in '99. It is now required by law in all cars sold in the USA. I spent half a year looking for the right '98 when I was ready to buy, no AH, shorter rear end gear otion, and the right color. It took a while, but I found it. and ended up defeating the anti-lock brake system too. The AH will apply brakes, the ABS will let them loose. After several near rear-enders from creeping speed I killed the ABS system, and have been driving with real brakes and no problems ever since! The next step will be re-plumb the entire brake system with a Tilton dual cylinder side by side master cylinder system and dedicated direct lines.

Mallett Z

Subscribed! This is interesting! someone I know has a story just like this but the income resulted in much less damage! glad your buddy is OK

As for my buddies case I have no idea about the conditions or how he was driving the car. He just says that the car went crazy and it caused him to loose control. To this day he says that car is cursed. I know the car had AH issues but i can't remember if it was after the accident or before.


makes me worry about my 02 Z06 because I currently have on and off AH/TC warning lights on the dash. Maybe i should check that yaw sensor out that is mentioned in the GM bulletin a few pages back.

FiberglassFan

Pull the wiring harness from the brake modulator system, or pull the fuses that feed the systems. That will kill the AH and ABS, and leave you with power assist brakes that only you the driver control, the way we drove for many generations. The brake system in the Corvettes is very easy to properly modulate without electronic assistance to let up or heave to in any suprise manner....from everday trunding around to the grocery store, or in very spirited/agressive driving.
You will have a light in the dash display that says these systems are foobar, but so what....If its irritating, pull the gauge cluster and remove those bulbs. Remember that the AH and ABS systems are brought to by the same engineers that figured out that wonderful steering lock system that the government finally mandated to be removed from our Corvettes because it had the strong potential to kill people WHEN in mis-operated...not IF,....WHEN!.

I love my Vette......don't get me wrong on that point! I just deal with its safety shortcomings with knowledge and by taking action to remove or defeat the systems that can kill people when they fail.

ZeeOSix

Scary !!

This has been going on (rarely) for some years now ... wonder if GM ever investigated on why this could be happening.

ZeeOSix

Related thread, and info on how to get to the yaw sensor.

http://forums.corvetteforum.com/c5-t...ore-codes.html

laurent_zo6

As someone who is looking to buy a 2001-2004 C5 Z06, your post has left me with a few questions:

1) How did you deal with the steering wheel lock problem (CBL or LMC5 or?)
2) What are the downsides to disabling the AH and ABS aside from the lights on the dashboard. Will the brakes work just the same? If I pull the fuses, do they only apply to those two system or they cover other system parts which I might miss then?
3) If I pull the fuses and the Yaw sensor fails or other parts of ABS or AH fail. Does it not matter since the system has been bypassed?

Dave68

If you have a 2001-2004 C5, there is no need to bypass anything but the column lock and that's a $50 kit solution. ABSFIXER will repair your EBCM and warrantee it for $150.

They repaired my 01's EBCM, many years ago and it continues to work like a champ.

laurent_zo6

Dave,
Thanks for the input. But isn't the point that you don't know when the EBCM is going to fail so better take preventive measure first. Once the car is damaged it might be too late unless you mean to take it to ABSFIXER even if the car runs fine so that they can check out the system. Not sure you can tell when a part is going to fail.

duramaxsky

I have an Early 98. The C6 has it but the C5s had the first experimental version. Now to see if the future holds this for the newer cars or they got it sorted out.

Dave68

Laurent,

I think it's safe to say that the chances of having a violent, out of control type of EBCM failure is extremely tiny. Once you remove the EBCM, those chances should be zero. However, you are far better off having the module repaired than you are to simply remove it and never replace it.

Dave

laurent_zo6

Dave,

I understand your point but how can you have it repaired unless it fails then it might be too late?

DBRASUE

Can anyone post a picture of the yaw sensor? Thanks!

Dave68

...too late for what? New EBCMs are available if you don't mind spending hundreds more.

jranaudo

This is great I just bought a 04 Z06 Lemans Edition and have pretty much spent another few grand getting it track ready. I only intend to track the car 3-4x per year but either way this is very dissappointing. I thought I researched every possible issue with the corvette but I somehow missed this. Now I think I know the reason most people that track their cars often are running 350's, BMW's and such.

Can someone post explicit instructions on how to disable the active handling system entirely?

Also when you do that how does it effect other system like Stability control, ABS, Traction controls? I think I trust myself and my driving capabilities more than active handling. I would rather crash due to my own driver error than to crash because some dumbass software developer created a poor system!

Phanni

You seem to assume the failure of the EBCM is not only likely, it is a given. That is not so, I've spent many week ends around autcrosses and high speed events. I have never witnessed a failure of an EBCM that is blamed on AN EBCM, in fact most experienced drivers turn off the A/H while competing. Most do use it when familiarizing themselves with a new track.

Arc07

They won't fix mine since I have the C1255 code.

laurent_zo6

Fortunately we have websites such as Corvette Forum to bring to your attention details that automakers are lax to do in order to maximize profits at the expense of the individual.
(only recall to my knowledge for the C5 is for the steering wheel lock problem). Are there any notices about EBCM problems?
EBCM failure will probably never happen to your car but it is not to be taken lightly since there is the potential for bodily injury at worse.
You can read about other drivers' experience regarding different problems and then make an informed decision as to how you want to proceed.

laurent_zo6

If no one has sent you pic yet you can go to Google images and type: Corvette C5 yaw sensor. Plenty of pics there.

Dobbinshabby

I actually had someone pull out in front of me on a rainy day and wasnt able to stop because my ebcm failed months ago and I couldn't find a new one.

My tires were locked up FOREVER.