ok im having a mass amount of trouble trying to figure out if te abs in my 99 frc can go bye bye. from looking at the schematics the steering wheel positioning sensor and brake pressure differential switch run through the ebtcm. now by completely deleting it will i need to reconnect those sensors to the pcm or can they go with the rest of the system. most of this stuff is used with active handling which i dont have.

 

Fix your ABS, I bet it will be less expensive than trying to get your car to work correctly without the EBTCM. The EBTCM talks to the PCM – BCM with a serial data line. The only way the PCM-BCM can get steering wheel position information is with serial data from the EBTCM. Of course you would also be killing your traction control as well without a EBTCM. I know there is a VSS sensor on the diff but I still think the PCM uses wheel speed sensors to figure vehicle speed. Again that info comes from the EBTCM to the PCM on the serial data line.

 

take out dash lights if that bothers you ?

 

Your not going to effectively remove the system. Its going to cause lots of problems. Yea,,there are C5 track cars without the system BUT,they have eliminated almost all the other Serial Data connected systems and use a stand alone PCM system to run the engine. Its a LOT less expensive to fix your issues.

BC

 

the system works fine im just removing to remove it. cars becoming track car, and theres only a few fnctions of it that are used if you dont have active handling. but either way i figured it out

 

Glad to hear you got it figured out. Would you like to share it with the rest of the group?

 

ABS doesn't hurt you when you are racing. You aren't going to save that much weight either. The EBTCM, the BPMV and some wiring.

Bill

 

Please share! Inquiring minds want to know...

I have an open circuit on one wheel speed sensor, not intentional, ..the yellow ABS and TC lights come on in the dash, it disables the traction control system which I love, but also disables ABS, which I like in wet Oregon for reasonable stops on wet roads....If were not for the ABS, I would just leave the wire connection broken, but I like ABS in wet weather. I would like to totally disable the traction control system, I'm tired of constantly having to punch it off every time I start the car....OK, I;m not having to do that right now, but when I fix that connection, It will be back to normal...

BTW, I would NEVER have a car with active handling....Had to search for the right older Vette when I bought mine, one made without A-H.
Traction control is bad enough....Have a friend who had an incident when the A-H decided to lock up a rear brake in a puddled freeway...Slammed him unto the guardrail and did 18K$ damage to the car. When I google for COrvette wrecks, then filter for no drunks, or obvius high speed, there are about 3 or 4 a week I find where the driver insists that he did nothing to cause the wreck..car just swerved on its own. Sensors and Computers fail all the time. Putting the activation of your brakes in charge of a computer is outright stupid..
Just this week a recent model Lotus swerved into a head on with another car, killing all 3 people. A witness reported that the Lotus just jerked with a skidding wheel. All newer cars at any price range are now requied by Federal law to have A-H...I'll pass, either by learning how to defeat the system, or by driving older cars and hoping that some newer car does not kill me unintentionally. I am an electronics engineer..I know how unreliable electrical and computation systems can be.....Just look at the huge number of post for failed engine, climate control, grounds, column lockss, and switch failures there are on the Forum....hundreds a month! You want that kind of reliability making decisions to turn your brakes on? Not me!!! Note ABS works by releasing brakes momentarily in a throbbing action...if the ABS system fails, you STILL have regular brakes action that works as your foot tells them to. A-H will apply a brake all on its own, to 'asist you' in certain cornering circumstances. When it fails, or gets confused by puddles on the road or a quick swerving lane change, it will STILL apply a brake, usually with dire consequences. It effectively destroyed my friend Mark's '02 C5. Fortunately, he was only lightly injured, and the car was rebuilt for 18K, then he sold it and bought a C4...

Anyway ...looking forward to hearing how you shut off the systems...

 

well i basiclly removed the abs side of the module leaving the ebtcm still right now the cars in a mass down stay for a turbo kit and motor build but once its up ill find out hows its working, tech2 should be able to shut it off.

 

Do you mean that the module has 2 circuit boards, and that you removed or disabled one of them? Just asking for some clarification...

In a perfect world...
1. ......I would make the ABS switchable, so I can turn it on when driving in wet conditions, or when for whatever reason I want it to be available, and OFF when I want real brakes under my own control.

2....and to NEVER have Traction Control in the manner it appears on our cars, nearly killing the engine when it triggers...
Launch Control, now banned in F-1 racing, is a different matter,...It is a useful version of Traction Control, unlike the C5 system...

3....and to NEVER have any Active Handling of any kind for any reason. If you can't drive properly, you ought not be under the control of a motor vehicle in a public venue.

Good luck in your Turbo install....Should be fun when done!
Jennifer

 

The Electronis portion of the BRAKE SYSTEM in our C5s utilize TWO modules (combined into one UNIT) to control braking. Here are the two modules:



The module halves are the Brake Pressure Modulator Valve on the LEFT & EBTCM on the right:



IF,,,,,,you "RIP" (its RTVed together) the EBTCM apart there will be a circuit board, coils a bunch of relays and a "micro processor"











If you dont want TC or AH to kick in,,,,,,why not just turn it OFF. Its MUCH simpler than trying to buck the system. There are LOTs of other systems that use the EBTCM to work properly.

BC

 

One thing AH cannot do is compensate for a person who doesn't know how to drive. It doesn't get confused by puddles. In rare occurrences it may fail in a way that causes it to activate at the wrong time. Everybody who says they fought with AH is suspect in my mind. If they are steering correctly AH will assist them. If they are steering incorrectly AH will assist them.

Bill

 

The way to make ABS selectable is to insert a toggle switch in the power line going to the EBCM. Run the wires from the wiring harness going to the EBCM to the dash and connect them to a toggle switch. When it is closed you have full capability when it is open nothing.

This is how Danny Kellermeyer turns the ABS on and off in his 99 FRC race car that he runs in the Touring Challenge for Corvettes. The ABS is sensitive to track irregularities that cause it to shut off when under power. When he gets an ABS warning he reaches over and throws the switch back and forth and the ABS resets. He uses it when road racing. But he is only a professional road racer and doesn't know any better.

Bill

 

ill take some pix and post them up but my abs mod looks nothing like the posted being i dont have AH.

 

the only other things that run through the ebtcm are the steering wheel positioning sensor, wheel speed sensors and brake pressure switch differential used only in (jl4) AH cars, the car has no need to know wheel position if a AH is not equipped. wheels speed sensors and bpsd go nowhere else other then to the ebtcm. yes the car will probly throw a light but i can remove the bulb, and hopefully the tech2 can just it or shut the system off. the cars a shop vehicle and wont being seeing alot of dd usage. but occasionallly will being driving on weekends and to shows /events.

 

The variable effort power steering gets its input from the EBCM as well.

Bill

 

One of the problems I have been researching is the inadvertent re-positioning of the 3 axis G sensor, just one of the input devices of the A-H system. When it falls out of it's cheap plastic mounting clip it sends erroneous positional information to the computational system and inadvertent application of the brakes can result.

Of course it could be argued that the electronics in the C5 are 100% reliable and NEVER fail for any reason under any circumstance and hence, can be trusted beyond the requirements of spacecraft or life support systems. I'm sorry, I just don't buy into that...I am an electronics engineer and I have some clue as to how electronics work and how they degrade and fail. Even with million dollar maintenance programs, we loose several fly-by-wire computationally assisted military aircraft a year from sensor or computer failures. If they can't even keep a well engineered unlimited budget aircraft from crashing, how on Earth can anyone expect a cheaply built, lowest bidder contracted, automotive system from crashing, especially when its expected to run essentially forever with zero maintenance. Most cars that the major makers build are designed for no more than a 10 year service life. Look at what goes in the crushers! The anomaly is the occasional collector/enthusiast car model like the Corvette, that tends to be preserved indefinitely, or at least until collision, fire, or some other catastrophe intervenes to end its service life. When you combine what I view as essentially disposable electronic systems with a long life platform, the electronics become the frangible element. We see this today with post after post after post concerning failure of electronic systems in the C5.....Our population of cars is starting to show its age, and as it does so, the limitations of low cost, cheaply made subsystems are being revealed. I understand the Forum is filled with supporters of of the 'engineering' behind the cars, people who believe that GM has only the best and top minds in the world, engineering the most reliable systems possible for our Corvettes, but the truth as I see it is that they do as little as possible. Just look at the notorious column lock issue that has plagued the C5 from the beginning of production What can be more simple than a servo motor and a peg to loch up the column, and they NEVER got that right. In the end the government ordered a recall, 04006-suffix C in the series of previous service bulletins, that mandated the outright removal of the locking plate system because it posed a safety issue. Even today GM is dodging the problem with dealers mis-informed about the suffix C version of the Recall, and not performing the necessary work unless an informed consumer pushes the issue. It has required a diligent and informed consumer to pressure and educate the dealers, often having to bringing a printed copy of the Recall/Service bulletin itself into the dealer, to get the recall work done. GM has fought us owners left right up and down on the simple column lock issue, .....Would you expect them to admit to flawed engineering on other more complex aspects of the electronics in the C5, especially those that impact life and death at an even higher level than the inadvertent locking of the steering column? Of COURSE the corporate party line is that all is just fine, all is reliable, and all is done for the good of the consumer.

Today we face a situation where the future of GM is in doubt,....they have been resistant to help owners with engineering defects in the past, and with the severe financial difficulties facing GM, perhaps even its demise, I would not trust them to come to our aid with open arms to fix the defects built into the Corvette. It is time that we as C5 owners faced up to the situation that these cars have potentially severe electronic issues that WE are eventually are going to have to address these issues on our own. It took an outsider to come up with a work-around, the CLB, for the column lock issue before the government FORCED GM into a program of outright lock removal....A program they have systematically drug their feet on compliance with. As other electronic systems in these cars come end of service life, far before the end of life for chassis, engine drive-train, and body, we will be faced with having to replace, remove or re-engineer these systems. In my view, some of these systems were under-engineered in the first place, and ought not to have installed in the car. Now it is coming to light that some of these systems are failing and in cascading frequency. What are we to do...stick our heads in the sand and insist that GM is the GOD that did it right and that all is well, or should we instead look at the truth, and figure out a methodology of extended maintenance, repair, or modification procedures that will make or cars safer and longer lived?
It should be pretty clear by now where I stand on the subject.

OK, I admit that a 'perfectly' working A-H system, can aid in car control in some certain circumstances, but I continue to argue that the prospects of keeping the system operationally 'perfect' indefinitely are impossible. I also argue that it is impossible to program such a system to respond correctly in every conceivable condition a car will be faced with during its many years of driving experience. Combine the 2 aspects of not being able to program for EVERY possible scenario, with a finite service live, and you have eventual doom. Sorry... I don't want it.

Its bad enough when the engine just quits and you have to spend a pile of dollars replacing failed electronics to get it running again. I do not want to be placed at risk with other systems failing that can have far greater consequences than an engine that just shuts off.

I do also want to make it clear that I DO support the notion of Anti-lock Braking Systems > ABS....This is the one single electronic aid to drivers that has had a virtually universal positive effect. It also has the aspect that when the system fails for whatever reason, that full manual control of the brakes is maintained. This makes sense to me in the trade-off between reliability and safety. You can STILL STOP, in a full system failure, albeit taking a few more feet to do so, but you can and will stop. This is known as Fail-Safe engineering and is the right way to do it.

Having a system in place, one of whose failure modes is to indiscriminately apply one or another of the wheel brakes all on its own, is to me, insane.

 

Asprin and tylenol have killed people too but what they and AH have in common is that they prevent more damage than they cause, and by a large factor. For every person that has been in a wreck due to AH, there have been hundreds where AH has prevented one.

And, even better, if you don't like AH, turn the thing off. GM has given you that choice.

You sound like someone on the forum before that didn't like the throttle-by-wire because the electronics can get screwed up and pin you at full throttle. They did not mention the fact that mechanical throttle cables can get stuck, too, and are much more likely to do so than throttle-by-wire.

 

The AH, TC, and ABS will turn themselves off if an error is detected in the system, so the potential for it to cause an accident is very low.

I too suspect that people blaming the AH or TC for a wreck are trying to rationalize that they are not at fault. You can get yourself into trouble real fast with the C5 even with AH and TC, and most will not understand what happened to them without some training in how to road race or autox. Street driving or drag racing alone will not necessarily mean you know how to drive around FAST, no matter how long you’ve done it. Some may, but your still better off finding out on a road race track or autox course. I'm no expert, but have spent the last a couple of years learning how to drive my Vette so I know a little about how AH/TC works on my Vette. Its a good system. And, FWIW a lot of road race instructors tell you to leave AH ON. Because knowing when and why it engages will help teach you how to be smooth, and smooth = fast.

IMO, before doing something highly questionable to your Vette, go to a HPDE or autox and take some instruction and learn how drive fast. You most likely will learn a lot and actually become FAST, and no matter what you will have an absolute BLAST doing it. Perma grin for days

For the OP, even in a track only car I would hesitate to think about removing the ABS. There are a lot of other places to drop weight if that’s what you are after. Do some searches in the drag race forum, there are a lot of knowledgeable racers around. If it is anything else, IMO most likely your just wasting time. IMO it would be pretty much the last thing done to a track only car, if at all.

Goodluck

 

IMO, one of the examples of a suspect report.