ABS on this truck is dangerous...

The VSC cannot override the rear brakes if it has been set with the parking brake. VSC works off of hydraulic pressure where the parking brake is a mechanical system. It can apply and release front brakes in this situation but cannot do anything with the rear brakes.

 

i was in line at tim hortons drive through today, i was crawling at 5kmph, there was a small patch of ice bside me where a puddle had froze, i had my front right tire on it, the other 3 on dry pavement, i touched the brakes to stop, and the friggin abs kicked in and i didnt slow down at all... i almost hit the car in front of me, i couldnt believe it.

 

WELCOME TO THE WORLD OF POS ABS

 

I had the exact same situation happen when I bought my Tacoma in 2007. Dry road, hit a frozen puddle with one wheel while lightly on the brakes approaching a stop sign. ABS kicked in, killed my braking power, and I coasted right through the stop sign.

 

Oh for FFFF sake! Why would you believe that?

It APPARENTLY DID function as designed.

Why is it so damned hard for you to believe that computer programmers suck arse? Why? Are you simply trolling or what?

 

I didn't describe anything.

It wasn't my truck.

And I thought it was me drinking bourbon tonight and "looking foolish".

Apparently I need to try harder.

 

WELCOME TO THE WORLD OF POS ABS U DBS

 

I'm going back to the kitchen to get another.

 

Awesome. Yet, please forgive me, it was a bit convoluted and not convincing enough.

 

There's the rub. It starts there with a big "IF" followed by endless pontificating.

How about starting instead with "IF" computer programmers suck ass then things go wrong?

 

I suspect the ABS and VSC problems are linked. I'm suspicious of the speed sensors at the wheels. In general terms, (ie I don;t exactly know how Toyota has placed the sensors, but the concept is the same) the sensor provides at least one pulse (probably two) for every rotation of the wheel. If a wheel stops or almost stops sending pulses as compared to other wheels, ABS kicks in. VSC is looking for the opposite state where one wheel's pulses increase in comparison to other wheels. (and also compares steering angles, throttle etc. to determine when one wheel is abnormally above speed)

In electronics, when receiving a pulse from a sensor, you would expect that to be simply a single, measurable, blip. The truth is there could be several blips within the single blip. It's most obvious when opening or closing a mechanical switch, but is also present for various physical reasons with non-contact sensing systems. If the firmware does not distinguish the 'bounces' in what should be just a single blip, and counts those as multiple blips, the firmware screws up. The firmware needs 'debounce' code that ignores the erroneous blips. This can be done wiht either hardware or software, but I suspect that is the first place a Toyota engineer should start looking.

 

This is the kind of stuff that is important to our discussion about the purported ABS failure in the tacoma.

I need to put aside my bourbon for now, along with my nail biter debate with DoorDing. This deserves a thoughtful reply.

Carry on ....

 

My philosophy is that software can only enhance a mechanical system (hardware). Maybe I'm too old school. Look at the hardware first.

 

Dude, I've had a bunch of bourbons. Whatever. I'll do the best I can!

 

in my language hardware is the sensor, wires, parts holding all that in place and specific electronic circuitry. Specific electronic circuitry (filters, derivative, integration, amplifiers) can be replaced by algorithms operated by code for the computer termed as firmware / software.

 

Hmmmmmmm

Yet we live in a physical world.

The algorithms are models, imperfect, of those physical parameters.

When we go beyond the assumptions of the algorithms then the model breaks down. Yet the physical would remain true, regardless.

An example might be all of the variables at play rolling down a hill on patchy ice and snow at 7 mph. A mechanical system simply stops effectively when the brake is worked by a human.

 

... the algorithm rolls you in to the intersection

 

How's your mom?

 

I will preface this comment with the fact that I am no auto mechanic, have fewer years worth of wisdom regarding the the subject than most. That being said, I think that most of the concerns come from lack of understanding (much like my own).

I think that ABS is simply a tool that people aren't used to and don't realize how it works (again not saying that I do). I have had my fair share of instances driving in snow and ice. I have also had my fair share of instances where I slid further than I wanted to because of the "terrible" abs system. This is my current Tacoma and my previous Honda Accord.

I will say that the times the abs kicked on I was going faster than I should have to be able to stop. I still was able to stop in time and in all the cases the truck stayed straight on the road. It definitely is a different feel but something you can get used to.

The most recent case was a day or two ago and we were coming to a stop on an overpass to get on the on ramp for the freeway. The cars in front of us stopped and I had a delayed reaction. I knew I was going too fast so my instant reaction was to hit the brakes. The ice told the ABS system to kick in and I figured oh great we aren't going to stop. I eased onto the brakes and just held a consistent pressure. The ABS was on the whole time bouncing back and forth between tires. The entire time I thought that my plate bumper was going to scrape up the back end of the mini van in front of us. Eventually we came to a nice even stop with room to spare.

Yes I could have probably stopped sooner without the abs, but would the truck have stayed straight and under control? That is the unknown. With stopped cars on one side and oncoming traffic to the other if I had locked my wheels and ended up spinning the result would have been bad. I still don't know if I like the ABS system but it seems that with a little understanding and some getting used to it could be beneficial in a lot of circumstances.

Not every system is going to be tuned correctly as we all know by the random warranty work that random tacoma owners end up getting. Not all of them are the same and I imagine those with serious problems need to have the ABS system diagnosed and tuned.

You also have to realize that Toyota doesn't design vehicles for educated, experienced, and cautious drivers. They can't, they have to put in features that will aid in the most avoided accidents for the broadest range of drivers. I can definitely see how ABS fits into that category.

 

Yo Door Ding.

I'm out buddy.

G-night everyone!