Sunday, September 13th, 2020

A View From The Pumps

A VIEW FROM THE PUMPS

GREGG MARRAPODI

BRAKING BY WIRE; THE NEXT GENERATION

Welcome to the 21st century where everything is becoming dependent on volts and amps. Today’s vehicles have gone from cable driven throttles to electric steering and now to electronic braking.

Electronic braking is not new, as a matter of fact it was available in the 2001 SL500 Mercedes. Here was the manufacturer said about their new system. “The company that invented ABS brakes, traction control and electronic stability has launched the worlds first production vehicle equipped with electronic brakes.” This system was touted as being faster, more sure footed, reliable and safer during emergency stops.

The brake pedal on the SL500 worked with a computer that told four fast acting valves exactly how hard the brake pedal was being depressed and how to slow down each wheel.

The “back up” hydraulic master cylinder would only come into use if there is a serious problem or electrical failure. With split second accuracy the system can change braking pressures for each wheel and change according to road conditions, both mechanical and environmental. That means stopping on uneven surfaces or a wet road.

Sounds good on paper but was a little premature twenty years ago. The result was that in 2004 680,000 SL and E models that were built in October 2001 were recalled. It didn’t really have the effect on the American market since only 140,000 cars with that system were imported to the states. The recall was announced as a voluntary recall by the manufacturer and not mandated by the NHSTA. That is known as keeping bad press out of the headlines.

All in all the concept was not bad and in the last 20 years electronic braking has been slowly and quietly becoming a very big part of automotive technology.

ABS braking was the really first marriage of hydraulics and electrons. When you put yourself into a skidding situation, it is electronics that pulsate the hydraulic

pressures to keep from a wheel locking up. And while the braking part is 100% hydraulic, it is the electronics that “dither” the hydraulic pressure specific to each wheel independently of each other faster than our minds can react or feet respond. Pair that with a program that can employ a brake, rather than release it to prevent uncontrolled acceleration issues on uneven or wet roads. Welcome traction control. When designed and built together as a combined strategy they make for a more safe and controlled operation of acceleration and braking.

Integrate this system with the new radar systems and “intelligent cruise control and collision avoidance” became vogue. Intelligent cruise control slows your vehicle down if you are encroaching up on a vehicle ahead of you without disabling the cruise control. Collision avoidance, stops you dead in your tracks if a collision appears imminent. But in all actuality your car is braking with or without your knowledge or input.

Beware of autonomy, it is sneaking up on us.

As for us in the trenches, it is continued training learning the in and outs of electric calipers, the expense of new

tools to control these same calipers that threaten to chop off fingers if said vehicle decides to exercise the caliper when your hands are in it. The cost of parts will skyrocket when all of these electronics are used.

Lastly watch for the little “P” button somewhere on the dash or console for that is the electronic hand brake that will keep you where you are when it fails.

As per usual my normal signatures are even more important.

MAINTENACE AND EDUCATION BEGIN AT MILE 000001

LACK OF COMMON SENSE WILL ALWAYS COST YOU DOLLARS AND CENTS

Be smart and be safe!