2000 540i BRAKE, ABS, and DSC lights on, HELP!!!

I think the sensers the "mechanic" is referring to are the brake wear sensors....although I think that would cause the BRAKE light to come on I doubt it would cause an ABS light.

Also, as I said before, engine sludge, while not good, does not automatically cause a catastrophic engine failure. Was it using a quart of oil prior to the Seafoam treatment? Did you use the Seafoam in the crankcase? Engine sludge typically stays put except when you try to clean it out. Indications of sludge causing problems are; smoking (due to the oil not draining out of the head properly and getting sucked through the valve guides), running hot (due to lack of the cooling benefit of the oil since it's being held in areas), flickering oil pressure light (again due to the oil being held in areas because it can't drain back peroperly), and engine noises (caused by oil starvation).

I won't have time today to take a tire off for a pic but I found a pic from a DIY thread that will hopefully explain.



The way the mechanic explained it to me was then when the new rotor went back on, the sensor was knocked loose and the coat hanger tool helped hold it in place so that is was not damaged. What I had seen (where the arrow points) was the sensor wire hanging loose. It was close enough to the rotor to damage it.

Also

Wow, did I really type "BREAK", instead of BRAKE. I know my typing is bad, but man. My fault.....

Originally Posted by Fleetman

I think the sensers the "mechanic" is referring to are the brake wear sensors....although I think that would cause the BRAKE light to come on I doubt it would cause an ABS light.

Understood. There are only two brake wear sensors (driver front and passenger rear), while there are four wheel speed sensors. In the wheels with both, they are innervated from the harness at the same junction box.

The brake sensor can set a BRAKE light while the wheel speed sensor might set the classic ABS BRAKE DSC trifecta (or ABS DSC bifecta), if broken.

Originally Posted by LoganWolf

What I had seen (where the arrow points) was the sensor wire hanging loose. It was close enough to the rotor to damage it

Well, you really should find time to paste a picture (I do it all the time ... see any of my threads for plenty of pictures) as you're wasting our time (and wearing us out) by talking about a sensor when you're pointing far away from the sensor (at the connection to the harness) - and you're not even using your own pictures.

And, you're not being explicit enough even with people who know the difference between a brake wear sensor and a wheel speed sensor (both of which are in the same general vicinity).

So as to not waste any more of 'my' time, I'll not respond until/unless you take the courtesy to post a picture. Lord knows, I've done that thousands of times and it 'does' make a difference in eliminating confusion.

Good luck though!

The picture DID look like the ABS sensor wire so I doubt your sensor problem is the same wire.....brake wear sensors always look burnt to me. I think the coat hanger trick he's referring to is to hold the caliper up so it's not hanging from the brake wear sensor wire....a sure way to damage it.

Sorry to post into an old thread, but I don't think my issue warrants a new thread of its own.

I'm new to the site and have a similar or same problem. I'd like to run my issue by you guys and hear your thoughts. I have a 2000 540i with sport package, auto trans, 150k. I had the transmission rebuilt two years ago.

I get the three light trifecta, but other issues accompany it. Note only do I lose speedo, but also lose RPM and temp. The gauges may intermittently come on during driving, then off again. I also get a console message saying "transmission in fail safe mode" and the transmission remains locked in third gear. After sitting with the ignition off for some time (an hour or so), it drives normal but the whole scenario repeats itself if driven more than 20 minutes or so.

I took it to an independent shop for a printout of the error codes. The mechanic also suspected ABS.