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ABS Bypass

41K views 14 replies 8 participants last post by  econoaddict  
#1 · (Edited)
Does anyone know if its possible to eliminate the whole ABS system where it will not show an abs warning light or brake light on the dash?

I've unplugged the wiring harness on my 2000 Silverado from the ABS thing-a-ma-jig on the frame and it effectively stopped the ABS from working, but left the brake light on the dash lit up.

I have a friend with a 2006 Malibu that has the ABS engaging every time she hits the brakes.I cleaned all the sensors and it helped a bit but still not 100%.

As ABS is a totally unnecessary feature of newer cars, I'd like to dismantle it on my daily drivers.

Thanks,
Pugsy
 
#2 ·
it's easier to just leave it hooked up unless there is a problem.. I don't belive that they are unnessasary.. when tires lock up, the vehicle will accelerate for a short period.

ABS works almost exclusivly with the wheel speed sensors, so if the ABS is malfunctioning, 1 or more of the sensors are bad
 
#3 ·
matt167 said:
it's easier to just leave it hooked up unless there is a problem.. I don't belive that they are unnessasary.. when tires lock up, the vehicle will accelerate for a short period.

ABS works almost exclusivly with the wheel speed sensors, so if the ABS is malfunctioning, 1 or more of the sensors are bad
If you are a skilled driver and you lock up in an emergency, you should have no problem backing off until the skidding stops. We've been doing it for years before ABS came out. I also find ABS in the snow is worse than w/o it.

I can't see how a car can "accelerate forward" with brakes locked up. I do understand that a skidding car takes longer to stop than a rolling vehicle.

The point is that GM sensors are crap and if I can bypass that end of it, I wouldn't have to worry about "wasting" alot of coin. Sensors that go bad in 2 years are not worth replacing IMHO. I just called my parts supplier and you have to buy the whole hub assembly at $225.00 to fix the sensor.

If I bypass the system, the brakes will function fine, just not sure about the dash lights end of it.

Pugsy
 
#4 ·
once you are skidding, there is less friction to slow down at first than just letting off the gas and letting the trans work., so the car could actully accelerate to some degree, not much, but enough to be considered the adverse effect of braking.. it would be even worse on a wet road.

being the sensors are a voltage generator, unhooking them would have an adverse effect on what you want to do, the only way to disable it, is how you did it, but as for shutting the light off.. pull the bulb out if it has 1
 
#5 ·
The problem was that I had the regular brake light come on along with the ABS light. If there was a malfunction in the regular brake system , I wouldn't know til I nailed someone.

Does anyone have any schematics on the ABS system?

Pugsy
 
#6 ·
matt167 said:
once you are skidding, there is less friction to slow down at first than just letting off the gas and letting the trans work., so the car could actully accelerate to some degree, not much, but enough to be considered the adverse effect of braking.. it would be even worse on a wet road.
Wow. You may want to reopen that physics book.

First, if your foot is on the brakes, the car CANNOT accelerate forward without some additional motive force. If you figure out a way to do that, you've solved the energy problem. The RATE of deceleration will be different, but the car is still slowing down unless you've slid over a cliff.

Second, if the friction of a locked up tire sliding on pavement were less than a tire rolling on pavement (even with the brakes applied), then there would be no need for wheel bearings and round tires.

Finally, do not confuse what your inner ear (or your butt) appears to be telling you with what is actually happening.
 
#7 ·
there is an extra force on the wheels under braking. momentum caused by weight of the vehicle , it's still a force on the vehicle .. I'm not saying that it is even very much faster, probably not measurable. if you hit the brakes, you start to slow down, if the wheels lock, there is less braking force to the ground ( less friction than if the tires were grabbing somthing ) and therefor, under the same force exerted from momentum with less friction, it could accelerate, but not to the point it was b4 the tires locked
 
#8 ·
The "Red" brake light could be turned on by the fluid level sensor, in the master cylinder, or the parking brake switch.

I have found the "yellow" ABS light on, to be a problem being caused by, different sized tires. Worn down on 3 and a new, or "spare tire" on the other one.

Larger than factory tires/rims can cause it to come on too.

It is not always a problem with a sensor.
 
#9 ·
Ok first off, the abs system in gm cars and trucks will light the amber abs light AS WELL as the red brake warning indicator. The same red light is used for the low brake fluid level and parking brake switch. There is no way to defeat the lights, other than pulling the bulbs, they are controlled by the body module. ""As ABS is a totally unnecessary feature of newer cars, I'd like to dismantle it on my daily drivers."" I would love to see your face when those big rear discs on that chev lock down and **** that thing broadside at 70 mph. Whooo hooo you better be a skilled driver.
 
#10 ·
enginejr said:
Ok first off, the abs system in gm cars and trucks will light the amber abs light AS WELL as the red brake warning indicator. The same red light is used for the low brake fluid level and parking brake switch. There is no way to defeat the lights, other than pulling the bulbs, they are controlled by the body module. ""As ABS is a totally unnecessary feature of newer cars, I'd like to dismantle it on my daily drivers."" I would love to see your face when those big rear discs on that chev lock down and **** that thing broadside at 70 mph. Whooo hooo you better be a skilled driver.
Ya, knowing how to drive and not relying on ABS sure is a nice thing.

Thanks for the light info.

Pugsy
 
#11 ·
A bit of advice but first I will respond to your original question.

As for a way to uninstall or disable the ABS System, On your 2000 Silverado, You cant, not without adverse effects... plain and simple, as you have already found out it will turn on lights, amber ABS AND Red Brake Warning.
There could also be other effects depending on the vehicle, for instance, do you have traction control...automatic 4WD all of these systems are integrated together.
You have apparently diagnosed the problem as being a sensor, I'm not sure how you came to this conclusion, because I'm pretty sure you dont have the proper tools to diagnose this concern since these are very high tech and expensive. and you are apparently not in the Automotive business or you wouldnt have said you unplugged the wire from the ABS THING-A-MA-JIG???? You would have called it by its correct name FYI its called an ABS Control module.
The issue we are concerned with is not your ability to drive.I too prefer a vehicle without ABS,in some conditions. So I drive an older vehicle that was never equiped with it, when in those conditions.
As for your friends car with the ABS issues...PLEASE LEAVE IT ALONE IF YOU ARE NOT QUALIFIED TO WORK ON IT!!!!!!!!!

I say this because not only could you cause other issues which eventually WILL cost her alot more money to have repaired by competant technicians.
You also stand the chance of putting her in a potentially hazardous or even, god forbid, DEADLY!!!!!! situation as she may not be as skilled of a driver as you.
Helping out a friend in trying to get their car to GO is one thing.If you dont completely understand the ENTIRE Braking system leave it to qualified personel. If it wont go its a minor inconvenience if it wont stop its potentially life threatening.
 
#12 ·
i fully agree with justacertifiedtech on this, have someone who has the proper equipment & knows the system look at it & then properly replace/repair the failed parts.

ABS has a propose, to prevent the tires from locking so you can maintain control. you can't modulate the brakes as fast as the ABS system can no matter how skilled of a driver you are. that grinding sound you hear & feel during an ABS stop is the system working, its applying & releasing the brakes around 10 times per second.
you can take 2 identical cars, both with properly working brakes, one with ABS & the other without. in a panic stop the one without ABS can stop in a shorter distance than the one with ABS. the one with ABS will stop with the driver having far more directional control. the benefits of being able to steer the vehicle out weigh a few less feet in stopping distance.

as far as disabling the ABS light, once the ABS diagnostic system check has been completed with no problems found, the diagnostic procedure for the light not working is quite short. 1, turn the key off for 5 seconds. 2, while watching the ABS light turn the key on. 3, did the light come on? no, replace the instrument cluster.
the last IPC we had to buy new was almost $1000.00. almost all of the components are surface mounted, so i don't think you want to play with it.

sorry, but if you want to drive a truck that doesn't have ABS, you'll have to go buy one that doesn't have it from the factory.

i am not looking forward to the day when both steer & brake by wire are common
 
#13 ·
matt167 said:
there is an extra force on the wheels under braking. momentum caused by weight of the vehicle , it's still a force on the vehicle .. I'm not saying that it is even very much faster, probably not measurable. if you hit the brakes, you start to slow down, if the wheels lock, there is less braking force to the ground ( less friction than if the tires were grabbing somthing ) and therefor, under the same force exerted from momentum with less friction, it could accelerate, but not to the point it was b4 the tires locked
Sorry, but that is not physically possible. The RATE of deceleration may change, but the car cannot accelerate. Get a G-meter and try it.
 
#14 ·
justacertifiedtech said:
As for a way to uninstall or disable the ABS System, On your 2000 Silverado, You cant, not without adverse effects... plain and simple, as you have already found out it will turn on lights, amber ABS AND Red Brake Warning.
There could also be other effects depending on the vehicle, for instance, do you have traction control...automatic 4WD all of these systems are integrated together.
You have apparently diagnosed the problem as being a sensor, I'm not sure how you came to this conclusion, because I'm pretty sure you dont have the proper tools to diagnose this concern since these are very high tech and expensive. and you are apparently not in the Automotive business or you wouldnt have said you unplugged the wire from the ABS THING-A-MA-JIG???? You would have called it by its correct name FYI its called an ABS Control module.
The issue we are concerned with is not your ability to drive.I too prefer a vehicle without ABS,in some conditions. So I drive an older vehicle that was never equiped with it, when in those conditions.
As for your friends car with the ABS issues...PLEASE LEAVE IT ALONE IF YOU ARE NOT QUALIFIED TO WORK ON IT!!!!!!!!!

I say this because not only could you cause other issues which eventually WILL cost her alot more money to have repaired by competant technicians.
You also stand the chance of putting her in a potentially hazardous or even, god forbid, DEADLY!!!!!! situation as she may not be as skilled of a driver as you.
Helping out a friend in trying to get their car to GO is one thing.If you dont completely understand the ENTIRE Braking system leave it to qualified personel. If it wont go its a minor inconvenience if it wont stop its potentially life threatening.
Warnings acknowledged.
I am not a certified tech but I am willing to learn. I believe she mentioned traction control so I won't be disabling anything on her car.
I would like info on test procedures or proper tools required to diagnose these sensors.

I've already removed and cleaned both front hubs/sensors and have been told there is alot of improvement but still a bit of pulsing in a non lockup condition.

BTW, the "Thing-a-ma-jig" shows how much respect I have towards GM's ABS systems. I have NEVER seen a problem like this on a rice burner.

Pugsy
 
#15 ·
123pugsy said:
Warnings acknowledged.
I am not a certified tech but I am willing to learn. I believe she mentioned traction control so I won't be disabling anything on her car.
I would like info on test procedures or proper tools required to diagnose these sensors.

I've already removed and cleaned both front hubs/sensors and have been told there is alot of improvement but still a bit of pulsing in a non lockup condition.
Pugsy

First thing I would suggest is that YOU test drive the vehicle.
It may not be "pulsing" due to abs issues.
Very very possible that the rotors are just badly warped causing a bad shake.
If it is just the pedal bouncing/pulsing it could be warped rotors or drums in the rear.