How does abs/trac work

[madsav]

Ok might be kinda dumb on this one but how does abs brakes work? and how does the trac control work?
And is it possable to fit trac control to a vt commodore with standed abs non trac

[accentstencil]

The ABS is a four-wheel system that prevents wheel lock-up by automatically modulating the brake pressure during an emergency stop. By preventing the wheels from locking, it enables the driver to maintain steering control and to stop in the shortest possible distance under most conditions. During normal braking, the ABS and non-ABS brake pedal feel will be the same. During ABS operation, a pulsation can be felt in the brake pedal, accompanied by a fall and then rise in brake pedal height and a clicking sound.

Traction-control systems utilise the same wheel-speed sensors employed by the antilock braking system. These sensors measure differences in rotational speed to determine if the wheels that are receiving power have lost traction. When the traction-control system determines that one wheel is spinning more quickly than the others, it automatically "pumps" the brake to that wheel to reduce its speed and lessen wheel slip. In most cases, individual wheel braking is enough to control wheel slip. However, some traction-control systems also reduce engine power to the slipping wheels. On a few of these vehicles, drivers may sense pulsations of the gas pedal when the system is reducing engine power much like a brake pedal pulsates when the antilock braking system is working.

I stole these descriptions from other sites so they are not my words.

[graham7773]

both controlled by the computer. ABS uses the sensors behind each wheel to detect when a wheel stops turning and reduces brake pressure until the wheel is turning again. It happens very quickly and can be felt as a very quick vibration. Trac is also controlled by the computer and does a very similar job but uses your fuel and ignition system to do it. Trac senses that your rear wheels are spinning or have lost traction and reduces power until the wheel or wheels have stopped spinning. That is why some people on this forum don't like it and turn it off. Bit slow off the mark. accentstencil beat me while I was writing

[madsav]

accentstencil ,Cheers mate that filled in the blanks for me alot lol

[Josheh]

I was under the impression with the VT/VX model Traction control works by cutting fuel to the vehicle until it grabs traction back, The Pump break system was only introduced in the VY/VZ range? Probably wrong though, Thought I had read it a few weeks bacl.

[accentstencil]

I was under the impression with the VT/VX model Traction control works by cutting fuel to the vehicle until it grabs traction back, The Pump break system was only introduced in the VY/VZ range? Probably wrong though, Thought I had read it a few weeks bacl.

Not sure about that but I do know the traction control in my old VT Acclaim was completely different to my WH Caprice. In the VT when I lost traction it almost died on the spot and in the Caprice the car slows a bit and the accelerator pedal gets hard so you can't press it further, much better.

[acarmody]

I thought it just retarded timing.

[11gothevt11]

The ABS is a four-wheel system that prevents wheel lock-up by automatically modulating the brake pressure during an emergency stop. By preventing the wheels from locking, it enables the driver to maintain steering control and to stop in the shortest possible distance under most conditions. During normal braking, the ABS and non-ABS brake pedal feel will be the same. During ABS operation, a pulsation can be felt in the brake pedal, accompanied by a fall and then rise in brake pedal height and a clicking sound.

Traction-control systems utilise the same wheel-speed sensors employed by the antilock braking system. These sensors measure differences in rotational speed to determine if the wheels that are receiving power have lost traction. When the traction-control system determines that one wheel is spinning more quickly than the others, it automatically "pumps" the brake to that wheel to reduce its speed and lessen wheel slip. In most cases, individual wheel braking is enough to control wheel slip. However, some traction-control systems also reduce engine power to the slipping wheels. On a few of these vehicles, drivers may sense pulsations of the gas pedal when the system is reducing engine power much like a brake pedal pulsates when the antilock braking system is working.

I stole these descriptions from other sites so they are not my words.

I have vt with abs
Light wasn't showing up on dash
Buti needed to slam my brakes on to avoid a crash
The front tyres locked up ??????
Is my abs stuffed?

[accentstencil]

I have vt with abs
Light wasn't showing up on dash
Buti needed to slam my brakes on to avoid a crash
The front tyres locked up ??????
Is my abs stuffed?

It sure sounds like the ABS is not working, I hope you did avoid the crash. Does the ABS light illuminate when you first turn the ignition on and all the warning lights come on?

[11gothevt11]

yeh abs light comes on the dash when tyrn the key
Also since i have owned the car its had a strange problem
When taking off at lights engine will cut out for a second but will restart itself....More like a real bad miss...Anyway when this happens abs off and trac off light comes on
Only very minor problem about once a month
I have changed crank angle sensor cam angle sensor..
But last time i went to auto elec no error codes?? A faulty abs wouldn't show up??? Or maybe only works when it feels like it...
Anyway i done a test when driving on dirt road at 20kmh slam on brakes only locks up for a split second.
Even on dirt roads a proper working abs unit won't lock up at all????????
Also i have seen you on heaps of post you know heaps about commodores
Instead of writing up a new thread...Have you ever heard a way to paint power ster res bottle??????
I want a way to paint it but still see the fluid...Seems impossible but have you ever read anything regarding this???

[accentstencil]

Do you feel the ABS testing when you take off after first starting the car?

[11gothevt11]

Do you feel the ABS testing when you take off after first starting the car?

How do i test this???

[accentstencil]

The ABS system performs a self check each time the car is driven. This can sometimes be heard (sort of a groaning noise) as well as felt, as pulsing through the brake system.

[TI3VOM]

My series 1 VT V6 Acclaim has ABS + traction control ABS will be felt as said before by the pulsation in the brake pedal and the light in the dash will come on traction control will cause the engine to misfire which cuts the power to the wheels and applies the brakes to slow the spinning wheels.

[TMM]

I'm pretty sure the traction control on VY and older commodores just closes the throttle body with the same actuator that operates the cruise control, that's why you can feel it fighting you through the accelerator pedal.

[11gothevt11]

My series 1 VT V6 Acclaim has ABS + traction control ABS will be felt as said before by the pulsation in the brake pedal and the light in the dash will come on traction control will cause the engine to misfire which cuts the power to the wheels and applies the brakes to slow the spinning wheels.

Please tell me more about testing the abs

All i know is sometimes when i brake i feel a heavy pulsation...
But only around once a month ...

[acarmody]

I'm pretty sure the traction control on VY and older commodores just closes the throttle body with the same actuator that operates the cruise control, that's why you can feel it fighting you through the accelerator pedal.

Cruise control can only pull the throttle body butterfly open, it can't physically push it shut. Cruise control just loosens the cable and the butterfly closes itself because of spring.

[TI3VOM]

Please tell me more about testing the abs

All i know is sometimes when i brake i feel a heavy pulsation...
But only around once a month ...

If you need to find out go for a drive down a very quiet road with no one around and jump on the brakes if you have ABS you will feel a pulsation in the brake pedal if not you will hear the tires locking up and screeching constantly until you fully stop.