See http://www.benzworld.org/forums/w163-m-class/1166641-ets-bas-warning-light-fix.html?highlight=brake+switch

My '99 ML320 ESP/BAS & ETS lights (but not ABS) came on with an old battery and after the truck had been idle a couple days. The owners' manual said the lights would come on if the voltage fell below 10v. I saw 10.25v while cranking and replaced the battery (at Les Schwab for $78). The light went off after several starts in a few days (as is common with automatic resets on the trouble codes) but came on as soon as I moved the steering wheel. This is making me wonder about the steering position sensor. These lights do come on after you disconnect the battery but turning the wheel to full lock should shut them off-not so today.
I just did my research on this helpful site and will replace the cheapo brake light switch. I could well have moved my foot about the time I moved the wheel. I'll leave a note if this works for me as it seems to have for others. I saw that other owners have found the steering angle sensor to be integral with the steering column, a $1000+ item of a major nature.
Any additional thoughts will be appreciated.

I am replying to my last posting because the replacement of the brake light switch immediately turned off the offending lights. I did not even have to wait until the computer got around to routine verification of continuing trouble. My day was made when I called the shylocks at MB and was told they had the switch for $14. I raced down there before they could figure out that they had misplaced a decimal point.

Replacing the brakelight switch: The switch is located above the driver's feet. Remove the cover with two Philllips to the rear and two black plastic plugs at the front. A carpenters flat pry bar readily pulls those plugs but you might not need to if you already have the replacement switch in hand. I took the diagnostic port off so i could drive down to pick up the part and the trick here is to slide the retention shelf sideways. The stoplight switch comes out by pushing the obvious tab and giving it a quater twist.

The cost of the switch was reasonable but it is not poorly engineered. It must be the hardest working switch in the whole car (which made it a likely suspect). It has a built in spring/collar which gets slightly compressed by the 1/4 turn, eliminating all troublesome play from the installation. It is almost as clever as those perplexing to reassemble cupholders.

This is a great website!!!!! I think I will add an incidental success story and a better forgotten pitfall story to the appropriate threads.

I saw a $100,000+, 6.3 liter, 508HP, AMG version of the ML when I picked up the part. I was well over 120mph in Montana (road conditions were not good)in my new 3.2 in 1998 when the radar detector alerted and I commenced braking. The warning ticket was for 97mph and the Trooper explained that not all the electronic geegaws in the world are going to help with my vertical center of gravity. I was stupid but learned. That 6.3 liter ML looked like Death incarnate as it probably will not offer a second chance.. Germans are smart but evil!

When you guys change or disconnect the battery, make sure you reset the steering angle sensor. It's standard practice for tne ML.

DL

I've just joined your forum and am very impressed with the wealth on knowledge there is on this site. Thank you for some very imformative and detailed answers to this issue. After reading all the posts, I will change by battery and then the brake light switch which I asertain are the most likely causes of these annoying lights. However, in additon to learning that the brake switch also causes the cruise not to function, would it cause the ABS to kick in even on dry pavement? This happens on occassion and usually is followed by a lack of power when accelerating which I understand from the owner' manual happens with a defect with the ESP system.

If anyone could shed light on whether I am suffering from a multi problem issue here or if it is still perhaps related to the battery, brake switch or wheel speed sensor it is much appreciated. Thx in advance.

PS my ride is a 1999 ML430 that I just picked up for 13K.

ABS wheel sensors can go bad also.

Post:
Vehicle speed sensor 'A' code P0500 (BAS,ESP,ETS,ABS - lights)

and as wet roads or water goes; affecting abs, dash lights etc, this is what I was told at late:
Remove the:
*left front wheel
*the plastic wheel well in order to gain access to the fuse/electrical
box remove the wire connectors and clean and dry the latter. Even
consider silicone if one suspects water seeping in thought the wheel
well and settling below the fuse/electrical box

See here I solved my problem:
Vehicle speed sensor 'A' code P0500 (BAS,ESP,ETS,ABS - lights)

2000 ML 320
Parked the car, set the parking brake and when I returned to the vehicle 1/2 hour later and restarted I backed up a couple of feet before releasing the parking brake. As I drove away the above mentioned gang of lights and buzzer went off and would not go away. I tried resetting the brake and releasing but nothing stopped it. I drove about a mile to my office with all on and the buzzer sounding. I have read where the brake lamp switch can cause the lights to come on but does anyone know what can make all of the above come on? The odometer just turned 100,455 on my 100,000 mile factory extended warranty. Weather was warm and sunny and did not drive through any water.

By2sellBut
If yours is an electrical short somewhere in the wiring harness. The dash lights can still be activated even without water or moisture.

Hello:

I own a 1997 S600, and i have the ABS, ESP light on.

I had replaced my battery with a new one, and i could swear the esp, abs came on after that, but it could be something else.

I did a search on here, and i tried the steering wheel trick, back and forth, but it didnt solve it.

Someone suggested that it could be a brake switch problem, but my brake function properly and lights come on. Could it be the brake switch, if the brake lights are functioning?

Now another thing of course, that it could be the battery. But the battery is brand new. I had it tested and it was putting out 12 or so, but at crank it was putting about 10.5. I heard before that if goes 10 or under that might activate those lights?

Another thing, i took it to my mechanic, and he ran the scanner on it, and he scanned everything, but he told me that he couldnt communicate with the abs, esp module to get a code or anything.

any suggestions will be appreciated.

One last thing since we are talking about esp, my suspension on the s600 are hydrophmautic with ads i think. I heard that sometimes the ads or suspension somehow might go in default when changing a battery and not function properly. Can anyone give me some insights on that.


Thanks guys

I also have the abs bas esp ets lights. I think my battery is ok at 12.6 volts. Took it to dealer. They scanned and found a problem with the egr. But they didn't give me any brake codes. They replaced the brake light switch in recall. I'm still having the lights. Could egr cause the three amigos? Another place pulled other codes. I do not have the abs pump code but I do have c1000 abs control module. Should I replace this? Also had c1141 brake pressure sensor. When I do the steering wheel thing lights go off but come back.
P2602
P2600
P2310
P2068
Esp module fault
P2036
P2001
C1000
C1400
C1141

I dont think its the abs pump bushing problem as I did not have that code.

Was quoted 728$ for egr valve

Ml320 2002 135430 miles