2008 Toyota Corolla No accelleration

Tiny
KRAMMUEL
  • MEMBER
  • 2008 TOYOTA COROLLA
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 31,000 MILES
Well this might be a fluke, but the car would start and idle just fine and I could feel the trans wanting to engage but not move. I step on the gas pedal but it wouldn't move and it seemed like I wasn't stepping on the gas pedal. Also, the engine light came on at same time it started doing that. Got it home finally and it actually acted like it was fine. So took it to Toyota and they said it had code po504. They said the brake light switch had to be replaced because it shorted out and gave false readings to the computer. Everything seems fine now but was wondering does this sound like a possibility? Or will the problem come back? I guess I am just trying to understand how the brake switch can cause that kind of problem?
Thanks for any insight on this
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Wednesday, May 19th, 2010 AT 11:56 AM

2 Replies

Tiny
CARADIODOC
  • EXPERT
Hi Krammuel. Welcome to the forum. Have you been watching the news about Toyota's problems? Since cars were first invented, the gas pedal has been connected to the engine by a simple, reliable cable that weighs a few ounces. Since then we have added power locks, power windows, dome lights, electric head lights, electric windshield wipers, sliding side doors, rear lift gates that open with an electric solenoid, automatic transmissions, and gauges on the dash that tell us how the engine is operating. What every one of these items have in common is they were very reliable, easy to diagnose, inexpensive to repair, and any do-it-yourselfer could do the repairs. What do they have in common on today's cars? Every one of them is now controlled by one or more of up to 47 computers that are extremely unreliable, impossible to diagnose without costly specialized equipment, and very expensive to repair.

Your car no longer has that simple, reliable, common sense throttle cable. Instead, your gas pedal turns a sensor that sends a coded signal to a computer that interprets it, (hopefully correctly), and sends a voltage to a motor bolted to the throttle body on the engine. The motor opens the throttle valve to let more air in, and the computer turns the fuel injectors on for longer pulses to provide more fuel at the same time. A second throttle position sensor on the throttle body tells the computer if the throttle is at the position the computer expects it to be at. If it is not, or if any other potential problem is detected, the computer disables the system, hopefully to idle, not wide-open-throttle, and you sit on the side of the road.

If all that ridiculous, complicated nonsense doesn't work properly, the brake light switch provides the signal to activate the fail-sage backup system that shuts the system down. Lucky for you that backup system worked, ... This time. When it doesn't work, you make the news. Of course we all know throttle position sensors haven't caused any problems in years past, (lol), so now we use two of them.

I get a chill up my spine every time I think about this system and how many of them are on the road coming toward me. It is used by almost every manufacturer and is one of the biggest reasons mechanics and other people who are knowledgeable about cars don't own or drive them. What IS surprising is that only Toyota has been in the news. Audi and Volkswagen have similar problems but they don't have non-union manufacturing plants in the U.S. So our government has no interest in attacking them. Toyota isn't doing anything different from any other manufacturer and they don't deserve the treatment they are getting. Nevertheless, we predicted many years ago people were going to die due to these computerized throttle systems, and my current prediction is there will be other manufacturers with similar problems in the future.

Sorry to be so blunt, but the average consumer in the U.S. Has no idea how much technology is in their vehicle. They only know that every time there's a problem, it's going to cost a lot to have it repaired. To answer your question honestly and politely, yes, the brake light switch can cause the problem you described, and is probably the least expensive part involved in the system. Hooray for an honest dealership service department. This is not a common failure item, so as for the problem coming back, I would not be too concerned. I'd be more concerned about a sensor failure, but to give credit where it is due, there are millions of vehicles on the road with this system and the percentage of failures is very small. (Of course there was 0 percent failure with a simple cable).

Caradiodoc
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Wednesday, May 19th, 2010 AT 3:40 PM
Tiny
KRAMMUEL
  • MEMBER
To start off: I do realize there is a ton of "electronics" in cars now and to many computers :) lol

I do appreciate the response and good details. That is what I was asking and got it. :)
I just wanted the reassurance of that being a possibility and that the dealer wasn't blowing smoke up my a**. Also, like to mention that it was under warranty and didn't cost me a thing (but barely, Toyota's warranty isn't that great. Imo).

Thanks again

PS: Agree about the cable being more reliable. But this is the 21st century and everything is computer controlled somehow.
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Wednesday, May 19th, 2010 AT 5:34 PM

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