FAQ: Anti-Lock Brakes and/or Traction Control Light/Lamp On

I was just curious about how our traction control works exactly and if there were any changes in any model years.

i'm not aware of any changes in the EBTCM (Electronic Brake Traction Control Motor) from 95-99. however since our traction control works by aplying the brakes, the newer riv with the larger rotors have a slightly more efficent EBCTM.

some trac. systems reduce spark, pull fuel, brake wheels or reduce the throttle position. i think ours only works with brakes but it may also use spark advance.

this is from the how-it-works site and it explains it better than i can

"Enter electronic traction control. In modern vehicles, traction-control systems utilize 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."

HTH Matthew

Mr.Riviera wrote:

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.

HTH Matthew

I believe the '95 uses the braking method and the '96 and newer use engine power reduction.

my EBTCM is connected in line with my brake system on the 96'. they may use both from 96+

Thats what I was thinking. I know the breaks are being applied but I wan't sure about any other methods used.

I know on my car it pulls timing. I used my ls1m scanner and my timing dropped down to 0 when the traction control engaged. I don't know if it applies the brakes or not.

TC uses both methods, depending on the situation. I think it's brakes first, then timing if needed.

From: https://rivperformance.editboard.com/Riviera-Talk-c4/Riviera-News-Reviews-f15/94-Riviera-Marketing-Video-t152.htm

racinfan wrote:

What is this "4 wheel traction control" feature mentioned in the video @4:38? Is it some sort of rare stabili-trak option or was it a blatant lie? Maybe they were referring to "2 wheel traction control" and wanted to make it sound more impressive?

ABS?

racinfan wrote:

What is this "4 wheel traction control" feature mentioned in the video @4:38? Neat video though.

Traction Control intervention can consist of any, or all, of the following:

1) Retard or suppress the spark to one or more cylinders
2) Reduce fuel supply to one or more cylinders
3) Brake one or more wheels

The Traction Control system shares the brake actuator and the wheel speed sensors with the anti-lock braking system.

deekster_caddy wrote:

racinfan wrote:

What is this "4 wheel traction control" feature mentioned in the video @4:38? Is it some sort of rare stabili-trak option or was it a blatant lie? Maybe they were referring to "2 wheel traction control" and wanted to make it sound more impressive?

ABS?

They had already mentioned ABS during that little floating features part of the movie. It is probably just traction control as we know it. It would be cool to have ESP though.

racinfan wrote:

deekster_caddy wrote:

racinfan wrote:

What is this "4 wheel traction control" feature mentioned in the video @4:38? Is it some sort of rare stabili-trak option or was it a blatant lie? Maybe they were referring to "2 wheel traction control" and wanted to make it sound more impressive?

ABS?

They had already mentioned ABS during that little floating features part of the movie. It is probably just traction control as we know it. It would be cool to have ESP though.

That would be great! Just think it: "Get the F*** out of my way" and the opponents change lanes... Or better, you could ESP some thought like "I need to lose this race and go get some groceries" and they do it! Imagine their confusion when one minute they were racing some Riviera, the next thing they know they're in the checkout lane!

deekster_caddy wrote:

That would be great! Just think it: "Get the F*** out of my way" and the opponents change lanes... Or better, you could ESP some thought like "I need to lose this race and go get some groceries" and they do it! Imagine their confusion when one minute they were racing some Riviera, the next thing they know they're in the checkout lane!

lionfish wrote:

racinfan wrote:

What is this "4 wheel traction control" feature mentioned in the video @4:38? Neat video though.

Traction Control intervention can consist of any, or all, of the following:

1) Retard or suppress the spark to one or more cylinders
2) Reduce fuel supply to one or more cylinders
3) Brake one or more wheels

The Traction Control system shares the brake actuator and the wheel speed sensors with the anti-lock braking system.

Right, that doesn't explain the "4 wheel" thing though.

[quote="racinfan"]

deekster_caddy wrote:

That would be great! Just think it: "Get the F*** out of my way" and the opponents change lanes... Or better, you could ESP some thought like "I need to lose this race and go get some groceries" and they do it! Imagine their confusion when one minute they were racing some Riviera, the next thing they know they're in the checkout lane!

X2

Didn't he say 'ESP'? What's ESP on a car?

deekster_caddy wrote:

Didn't he say 'ESP'? What's ESP on a car?

haha, I thought you were joking. It's "electronic stability program."

Lol...

lionfish wrote:

racinfan wrote:

What is this "4 wheel traction control" feature mentioned in the video @4:38? Neat video though.

Traction Control intervention can consist of any, or all, of the following:

1) Retard or suppress the spark to one or more cylinders
2) Reduce fuel supply to one or more cylinders
3) Brake one or more wheels

The Traction Control system shares the brake actuator and the wheel speed sensors with the anti-lock braking system.

Right, that doesn't explain the "4 wheel" thing though.[/quote]

3) Brake one or more wheels

Yes, and we only have 2 drive wheels. The rears have nothing to do with it, hence my confusion with the "4 wheel traction control" feature.

From the '95 GM service manual GMP/95-G-2F (book 2, Page 8A-44-1):

The most common and well-known traction control device is the Anti-Lock Brake System (ABS). ABS is designed to prevent four (4) wheels from locking up during panic or hard braking. When braking, if your front wheels lock-up, steering control is lost and your car will continue in the same path as before you attempted to brake. The system consists of a host of speed sensors and a central computer. Speed sensors are located at the wheels of the car, which tell the computer how fast they are turning. The computer constantly evaluates the speed of the vehicle and the speed of the wheels. When the brake pedal is depressed and the speed of the wheel reaches or get close to locking-up, the ABS computer will then modulate the amount of brake pressure (or “pump” the brakes), as fast as fifteen times per second, on that wheel. This continuing modulation or pumping will prevent or correct wheel lock-up and allow the driver to brake and steer.

Traction Control is used to prevent the wheels from losing grip when accelerating. Spinning tires during hard acceleration may be dramatic, but it is the slowest way to get to your desired speed. Using the car’s ABS speed sensors at the wheels, the Traction Control computer compares the drive wheel’s speed to the car’s road speed. If there is a loss of grip event during acceleration, there are a number of ways that the Traction Control slows the wheels so they can regain grip. The most common method is to use the braking system on all four (4) wheels. When the wheels lose grip, the ABS computer can apply the brake to the wheel that has lost grip to slow it down so it can regain grip. Another method for slowing the slipping wheels is to reduce the amount of power applied to them. The computer will electronically modify the amount of fuel entering the engine and/or use the transmission to slow the drive wheels so they can regain grip.

Once again, the braking action is only done on the DRIVE WHEELS. For an AWD car your copy/pasted information would be correct. I'd love to see the source of the information as well.

i still dont see why the trac off light turns on when the CKP sensor misreads. got any more info on how our cars pulls fuel? and can anyone check the service manual for the 96+ riv's to see if there are any differences in the way the trac ctrl operates.

ABS on our cars is 4 wheel, but the ABS on my bonnie was 2 wheel as the dang thing still had rear drums.

I wonder about this 4 wheel traction also. They must have been applying that phrase to ABS only as TCS on the rear wheels that have no power would be more of an ESP system. I don't think the rears get factored into the TCS, only the ABS

I think the rear wheel speeds might be factored into the TCS calculations. It would help the system figure out if you were spinning one or both wheels, how sharp of a corner you are going around, etc...

Oh yeah, that would make sense. The rears should only be spinning as fast as the car is going. So you could call it 4 wheel traction.....

I dont know if any of you noticed this but if you push the button to turn off traction control and then spin the tires to above 50, it still engages the traction control (not by using the abs system though). If youre on snow and gun it, you can clearly tell. the engine will sound as if its hitting a rev limiter. The only way ive found to fully disable the system is to remove the abs fuse.