If he is talking about what people told us, it means the little lever that is right behind the brake pedal that engages the brake lights.

 

^^ you sure? That's not a level sensor. That's would be a sensor to tell the ecu you activating the brake.

There should be brake fluid level sensor on the master cylinder. In theory I could maybe see that affecting the vdc system. As it might not want to engage if there isn't enough brake fluid.

 

Hey, now! I said IF he was talking about what we were told. LOL I'm not certain that is what he meant.

 

I've got a module in my car now that intercepts and modifys the brake signal going to the ECU. Before I installed it I could NOT brake boost the car (apply the brake and throttle at the same time). As soon as I would press the brake the car would not allow me to accelerate any higher then I already was.

With the module, I can now accelerate while the brake is pushed in, allowing me to maintain a low speed, but high boost (perfect for highway launches at 40mph). Best of all, no codes, no lights, everything works as factory (even the speedo and the rear brake lights).

 

Cool! You sell this module? Can you confirm which brake signal you are referring to? Brake switch or brake fluid level? Thanks!

 

No, its not for sale (yet). It is waiting to be tested on a 5AT tranny to make sure it will allow standing wheel movement.

 

The brake signal I was referring to runs from the brake pedal to the ECU. It is how the ECU knows the brake is being pushed.

 

Kevin, here soon you should just offer a new BCM with all the mods in one!

 

Hey Kevin, great meeting you this weekend with Dan, and hopefully can get one of these over to me soon too!!

 

The brake lights are engaged by a small pin switch that is held down by the brake petal arm and comes on the second the petal is depressed. If you remove that switch the brake lights will not come on.

 

is there only one switch? ie.. that one tells the lights to turn on and also tells the ecu that the brakes are being applied? That would suck. I was hoping for two switches.

 

There is only one physical switch down there that I have ever seen. If you have a problem with the brake lights, your VDC, SLIP and ABS lights should come on.

 

Most drag racers use a "Line Loc" to keep the front wheels from rolling in a burnout.

The Line Loc is a solenoid by the master cylinder that the front brake line routes through. The solenoid locks the pressure of the front brakes when a switch is pressed. Most people use a small micro-switch mounted on the shifter to activate the solenoid.

So, the process for a burnout would be... Back the car into the water... shift into the gear you want to heat the tires with... step on the brakes... press the line loc button to lock the fluid in the front brakes... then release the brake pedal and do the burnout.

Line Locs are also used to keep the car from rolling at the Christmas tree. If you like to stage very shallow, even the smallest amount of rollout can turn on the red bulb. Remembering to release the Line Loc button when you let out the clutch is required.

 

Well, on my car there are two push switches on the brake pedal. The higher one being the one for the brake light. That's the reference that the ecu uses to cut the throttle if both brake and gas are applied at the same time while the tires are spinning at a higher rate than the front. I used a kind of OEM looking lighted switch along with a relay to bypass that signal on command, like at the dragstrip. There are no lights or faults associated with this when I hit the switch, because all I'm doing is bypassing that push switch.
It rained this morning so I went out and tried it, and it works perfectly. Hit the switch, hold the brake firm and gas at the same time with your right foot (around 3500rpm) then dump the clutch. The car shouldn't move.

I have some pictures of the process if somebody want to see them.

 

I'll have to try that.