I think this problems started a while back. We put a new set of front brakes on my son-in-law's 4-Runner. He had waited a few days too late and worn out pads cause the rotors to be ruined. During the exam of the rears they appeared to have a good 1/3 or more pad left on them. A job for another day. A week later the left-rears are eating into the rotor. After replacing them, (and a year later) the left rear rotor is being eaten up again. At the time I suspected the little stainless slide covers that the pads ride on (worn out and crunched up a bit) were holding the pad in a way that bound them against the rotor and did not let them return when the caliper was released. We replaced the pads again along with the new stainless sliders and a rotor. After a few days Chris said it felt like the left rear was making noise. The caliper moved in and out very smoothly but he decided we should replace the rubber brake line to that caliper just in case it was the problem. I agreed it was one of the cheaper ways to eliminate a possible sticking caliper problem. That new line is on my tool box now. But I found out a day ago that the ESC light is on. He won't say how long it has been on. He was told by someone at the dealership it was emissions related and usually the gas cap is the problem. He bought one at the dealership and thought it was fixed because the light was off. When I checked the 4-Runner for problem codes there was none. I told him the ESC light indicates that the electronic stability control is acting up and that it could be the reason for the left rear brake keeps wearing out.
My question. What sensors would cause the ESC light to come on indicating a problem and how do I test them? The truck drives fine and the left-rear rim/tire does not feel hot to the touch when I have test driven it. Thanks
Sorry, I forgot to mention his 04' 4-Runner has about 100,000 miles on it. It's due for a timing belt so we might let the guys at the shop who replace the belt(s) give us an idea of what the ESC problem might be. I just want to know as much as I can so he does not get screwed over by the service writer.