when i start my 4runner its fine, when i turn off the parking brake the light turns off, but then i start driving and it will come back on even when the brake is all the way in. Then when i come to a stop sign it turns off, then back on when i accelerate. Is there a sensor that could be messed up, possible electrical problem in the dash cluster, or even my brakes need to be changed? im not very familiar with the electrical system on my 4runner, its my first one. any possible diagnosis would be greatly appreciated, its very annoying to see that light come on while im driving, it worries me lol. 1991 Toyota 4runner sr5 V6 4X4 A/T in case that is necessary
Brake Warning Light Comes On
- Thread starter Nate613
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Carolinafan
New member
My 99 does the same thing, but only when it is cold. It will cut off after a second or two. I would like to know what causes it though...
TechWrench
Senior Member
There should be a fluid level sensor in the master cylinder which one of the computers monitors. If fluid level drops below set level, idiot light on dash will light. If this is cause, don't just fill master cylinder to 'fix' idiot light. Low fluid level usually indicates brake pads/shoes are worn and need to be replaced, or there is a possible fluid leak in system. Either way, it should be checked out.
like how you said "idiot light" not very friendly, thought this was to help out your fellow toyota lovers, not everyone on here has owned a toyota, i use to go american, had an 84 ford bronco with rancho suspension, it was nice but too old so im turning it into a pre runner, now that i have this toyota im doin my best to learn how to work on them, dont be an ass about it. but thank you for you input, we will see if you are correct. reason i didnt know exactly what it meant is cause i have seen a few people, including my self, have the brake aka idiot light, a/t oil temp, and battery light come on in various combinations which was the alternator. not to mention i did install a siren that works with key or not and wired it myself thought that coulda been the problem, once again not everyone has had a toyota 4runner and i sure as hell know not everyone knows how to deal with wiring.
TechWrench
Senior Member
At first, I was going to apologize for your lack of understanding/knowledge, but after re-thinking I don't feel I have anything to apologize for. I used the term 'idiot light' to refer to the warning lamp that is on the dash display. I don't know how old you are, not that it really matters, but I have been working on vehicles for almost 40 years, and that term has been in general use, to describe any dash warning lamp, for longer than that. It was not meant to infer anything about you. If you truly want to learn about your Toyota, I suggest you do more reading, a lot more. And try to not let your thin skin get in your way. I gave you good info, what you chose to do with is up to you.
i understand that, i do read up about it, i have a haynes manual and i have done alot of mechanical work myself. unfortunantly it does not describe slang. not my fault i havent been doing it for 40yrs, im sure if i had i would be up to date on the nicknames for everything, but then again whats the point, if you can get the job done doesnt really matter. by the way im 23 and i have had it for about 4 months, carbuerated mototrs is what i know most abut but not evreything. new to the toyota and i love it, so the least we can do is pretend like i knew wht you meant lol. my fault to jump to conclusion and automatically assume you are calling me an idiot. just realized right now as im typing anyone who drives with their parking brake on is an idiot lol, could that be why its called that? and by the way, advice was good, no hard feelings. i fixed the problem by changing and bleeding the brakes. hopefully that solved it and there isnt a leak. i come here to learn that is all, thatnks for the help man.
TechWrench
Senior Member
OK, no problem, we're good. There are several 'stories' or myths about how the term 'idiot light' came to be, none of them very flattering. In the end, I guess it doesn't really matter. The important thing I would stress it don't ignore them. No matter the reason, if one goes off, it (IMHO) isn't something to be ignored. Another piece of advice I would give is to read the owners manual, if you have one (and if not, try to get a copy online). It will explain all the warning indicators and gauge functions on the vehicle. Even with years of experience, it is possible to not fully understand exactly what the 'idiot' light or gauge on a particular vehicle is trying to tell you. Many older vehicles only had one indicator lamp for a brake warning, and they used it to indicate both a brake system problem and the status of the emergency brake. Most newer vehicles now use two separate indicators, and if you are not familiar with what they each mean, it could lead one to check the wrong part of the brake system. From my many years of working on vehicles, and other mechanical equipment, I have learned that to properly diagnose problems one needs to understand how the system indicators work and what event will set them off. It isn't easy. I have been doing this for over 40 years, and still learn new stuff all the time. Thats why I spend so much time here. Sometimes I can help others, and sometimes they help me.
