So, I just recently got a 2007 G35 S with about 51,000 miles on it. Love the car, so much fun, but has its share of issues. First off, being the ABS, SLIP and VDC off lights would come on randomly when on the freeway. Researching this for a while came up with all kinds of possibilities, from low fluid to low brake pads to anything else. Well, I think I found the problem with mine, and I thought I'd share for anyone else to add to the possibilities of what could be doing it.

I recently came out to my garage one night and found that the brake lights were still on from when I drove it home. I got in the car and hit the pedal a few times to make it go off. I knew that I needed an adjustment on the cruise control brake switch, because the cruise wouldn't engage without lifting the pedal with my foot. That got me thinking right there that was the ABS light problem.

So today going to work, I thought I would try to hold the brake pedal up with my foot the whole way to see if the ABS lights wouldn't come on. (because I've already tried that with the cruise to make that work) What ended up happening is coming off a ramp merging onto another freeway I had to accelerator! The car wouldn't go! I put the pedal down and it did nothing. Needless to say I was a little freaked out trying to merge going going about 20 mph! At that time I didn't put 2 + 2 together that it was related to my brake pedal, but I pulled off to the side and looked and sure enough the brake lights were on. At that moment I couldn't get them to go off by hitting the pedal like i had the other night, so I limped it off the freeway. It was then I realized that I could hold the brake pedal up with my foot, and as soon as I did that the car took off!

In looking at it, it seems the brake pedal doesn't come all the way up like it should. I comes up, but then hangs down with about 1/2" of play which is just enough to make the cruise not work and the brake lights on. I see that the cruise problem is fairly widespread with those cars, and is usually fixed by adjusting the switch. But I feel the root cause is that the pedal is hanging down a little bit which the switch adjustment just masks. I guess the easy fix would be to just adjust the switches and move on with life, but I think I'd like to look at the play in the pedal to see why that's there. Maybe tighten the tension on the spring or something?

Anyways, I thought that was interesting, and I thought I'd share this with others who may be having those lights going on themselves and are having a hard time trying to find the cause.

 

What a weird problem to have, thanks for posting. Please update this thread when you finally find out what the issue/fix was.

 

Check for 2 rubber bumpers on the brake pedal that activate the switches.

 

Sounds like a brake switch issue.

 

Update on this. So, this weekend I finally looked at it, thinking I'd go after that top play in the brake pedal. But looking at that mechanism, there's really no way I could see clearly what was going on. It seemed to be more that the mechanism was just worn, and the play was from worn pins and stuff, because it looked like the master was pushing the pedal back as much as it could. Funny, considering the car only has 55k miles on it. But, I gave up quickly on that, and decided to just adjust the two switches, brake and cruise. Also made sure to note that the rubber bumpers that those ride on were still there, which they were.

So, adjusted the two switches and now everything is back to normal. And since I did that, the ABS et al lights have yet to come back on. So I'm happy about that!

I guess to anyone else out there that can't figure out the ABS etc lights, check your brake switch! You may not even realize it's out of adjustment! Hopefully this helps someone.

Thanks

 

Your welcome....