Ok where do I begin? First, my 2001 ML55 has 225,000 miles on it. After a problem with the "sending unit" (per the mechanic) failed and did not relay to my dash that my engine was overheating, the engine blew and I found an engine with 30,000 miles on it so $7,000 later, the engine was replaced. After that was squared away, the brakes kept locking up mid-driving. I'm talking 60mph jamming to my favorite song and all of a sudden... The brakes were pumped! Tire streaks on the road and everything. Scared me nearly to my grave. Luckily, there was no one behind me. I turned the car off, waited a few minutes, started it back up and tried to get home. After 5 or so minutes, same thing, but I was driving slowly just in case. It happened at least 7 times before I made it home. I noticed that the ABS, ESP lights all lit up only when this was happening. After reading online and snooping around in the fuse box, I decided "what the hell" and removed the relay switch that was labeled "ABS/ESP". I did a test run around the parking lot and all seemed well. Hasn't locked up since. I called a dealer and was told that this was a bad "lateral acceleration sensor" and that it was merely coincidence that it quit locking up and that removing that relay switch had zero to do with stopping the issue. I know for a fact that this relay switch removal stopped it! It's not a coincidence that the lit up light and relay switch with the same label are related. I've just been letting it ride. Only problem is, the ABS/ESP lights are constantly lit up. Not causing any problems so I've just been driving and if the lights are the only issue with it, I'm cool.
Any thoughts on this??
Keep in mind that I'm just driving this car until it falls completely apart, giving it routine maintenance and upkeep. Not trying to spend anymore major money on repairs after the engine fiasco. Just trying to make sure this issue isn't going to blow me up someday soon.

Next. Recently, while driving, the emergency brake light will come on, another light on the dash with a large circle in the middle and 3 little notches on each side of the circle comes on, an audible alarm beeps for a few seconds, the speedometer quits working, and the ride feels like I'm having to give it more gas, like it just doesn't want to go but nothing dramatic. All this happens simultaneously. If I turn the car off and back on, the problem is gone and may not occur again all day. Or it may happen 10 minutes later. If there is an alarm sounding, it's got to be important because it's more than just a light so it's clearly trying to get your immediate attention.
Any ideas on this one too??
Like I said, I can deal with lights and I'm not pouring tons of money into this beast anymore. Maybe the car is just too old and the parts are failing one by one due to wear and tear and will eventually need replacing. I mean it's almost at a quarter of a million miles (but with a fresher engine) and I don't know the "life expectancy" of these cars with normal upkeep. It may just be time to retire the demon.
But in the meantime, I'd appreciate any feedback or ideas you guys may have.
Thanks guys,
Adam

 

Your problem is with the Yaw Rate Sensor, not the Lateral Sensor.