Toyota brake question....

[Beefcake]

Here is my question: On the new cars do the brake and gas pedals actually connect to the engine / brake cylinders? Or do they connect to a computer that in turn commands the gas/brake?

[Denholm]

I'm wondering the same thing. Personally I believe a Drive-by-Wire system is connected to the brake and accelerator.

[uptown]

From the ones i've seen, they have a throttle cable and fluid running the brakes like most all cars. I'm thinking the computer is telling the throttle position sensor to accelerate. The brakes are anti-lock and will have wiring involved in that. I'm almost convinced Toyota has a computer problem. Not faulty floor mats or pedals.

[Widewing]

Here is my question: On the new cars do the brake and gas pedals actually connect to the engine / brake cylinders? Or do they connect to a computer that in turn commands the gas/brake?

Drive by wire throttle is purely electrical (sensor based), with no mechanical link to the engine from the pedal.

Some manufacturers feature an E-Safe system. IE: Above a certain speed, stepping on the brake pedal bypasses the computer and sets engine speed to idle. Toyota doesn't offer that on most of the their car and truck line.

Brakes will always be operated by driver input as the primary input. However, various brake assist systems supplement driver input. Should the computer fail, you'll still have brakes, without ABS enabled.


My regards,

Widewing  

[morfiend]

From the ones i've seen, they have a throttle cable and fluid running the brakes like most all cars. I'm thinking the computer is telling the throttle position sensor to accelerate. The brakes are anti-lock and will have wiring involved in that. I'm almost convinced Toyota has a computer problem. Not faulty floor mats or pedals.

 I believe this has been shown to be the case,of course Toyota says the tests weren't "realistic".

 I dont think toyota uses a drive by wire system for throttle or brakes,but most modern fuel injection systems the throttle only controls the airflow and the computer determines the amount of fuel to add!

 I'm sure the more mechanicaly inclined will have more to add to this of course.

  

[Beefcake]

My father and I were having a conversation talking about how older cars are safer, and how these new cars you can't trust since we don't have direct control over the pedals. We weren't sure if the driver had a "direct" connection to the engine or not.

Awhile back I noticed my brake pedal on my old 1998 dodge ram was feeling "odd" and it caused me to check it out. Turns out I had a leak around the master cylinder which led me to replacing it due to it's age. I could feel my brakes weren't "right" just by the way the pedal was acting when pushed. I'm afraid on these cars you wouldn't feel that until it's to late.

[whiteman]

The ones having the problems are all sensor based, no wire or mechanical linkage what so ever. I'll take my caveman car with cables and push rods and be happy.

[68Wooley]

The V6 in my 2006 RAV4 is the same basic 3.5 block that's used across the Toyota and Lexus range. Throttle is electronic, brake isn't but (like most cars these days) has ABS and stability control systems.

I've owned three different Toyotas and if they actually made a car I was interested in right now, I quite happily go out and buy another tomorrow.

[Denholm]

My father and I were having a conversation talking about how older cars are safer, and how these new cars you can't trust since we don't have direct control over the pedals. We weren't sure if the driver had a "direct" connection to the engine or not.

Awhile back I noticed my brake pedal on my old 1998 dodge ram was feeling "odd" and it caused me to check it out. Turns out I had a leak around the master cylinder which led me to replacing it due to it's age. I could feel my brakes weren't "right" just by the way the pedal was acting when pushed. I'm afraid on these cars you wouldn't feel that until it's to late.

Absolutely true. We encountered a similar problem which could have resulted in brake failure. We've got ABS, like most modern vehicles. Pedals were operating just fine, vehicle was slowing just fine, except the Brake light was illuminated. Looked under the hood to find the master brake cylinder empty. It's absolutely ridiculous how little feedback there is for the driver. In some cases, I'm sure the lack of feedback has resulted in serious injury or death.

[nirvana]

The brake light was on, the sensor did what is was supposed to and alerted you to a problem.

[Denholm]

Yes, but it came on plenty of times before and we detected no problems (yes, we checked everything). The fact of the matter is, if the brake light comes on whenever it pleases, people will be inclined to ignore it. Therefore I find brake pedal feedback (such as sluggish response) combined with brake light illumination to be a greater indicator than only the brake light illuminating. If we didn't stay vigilant and check our system every time the light came on, we would have ignored the situation and plowed into something (or perhaps someone). ABS is great, yet its feedback lacks.

[dedalos]

The ones having the problems are all sensor based, no wire or mechanical linkage what so ever. I'll take my caveman car with cables and push rods and be happy.

As we all know, cables never fail 

[Skuzzy]

All cars, equipped with some type of electronic traction control system, will have a computer controlled throttle with no direct physical connection to the gas pedal.  It has been that way for years.

[Strip]

All cars, equipped with some type of electronic traction control system, will have a computer controlled throttle with no direct physical connection to the gas pedal.  It has been that way for years.

Skuzzy, this is not really the case...

For instance my 00' Grand Am has traction control, it has a standard cable linkage as well. Most of Pontiac's other offerings had the same feature, as well as hundreds of other vehicles. They use timing and dropping spark/fuel to certain cylinders to prevent or control wheel spin. It is true that many of the higher end sports cars with traction control will be as you described though.

Strip

[whiteman]

As we all know, cables never fail  

maybe but a cell signal phone isn't going to make a cable flip out.