After replacing the battery you must re-activate the Steering Angle Sensor as follows:

1. Start engine.
2. Turn steering wheel from lock to lock.

The ADS or ESP malfunction indicator lamp (A1e27 or A1e42) should go out.

At this time it may also be the stop light switch.

Hope this helps.

Rene

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'99 ML320, '00 C280

I also have a 99 ML320 with consistent BAS/ESP/ETS lights on. The other thing that happened at the same time is that the cruise control no longer functions. Lights came on all at once and have never gone out.

Took the car to the local independent MB shop where he used the computer to check codes and told me it was the steering angle sensor...requiring replacement of the whole steering column. However, I had not realized the cruise control was out at that point so I'll have to talk to him about it before he goes ahead with the repair. He did try the reset business with turning steering wheel lock to lock etc with no change.

I was with him when he checked the computer and saw the code for the steering angle sensor. When people are talking about replacing the brake switch, is that in lieu of checking the computer codes? Do the codes mislead? I'd hate to pay for the whole steering column replacment to find out I just needed a new brake switch.

I would replace the Brake Switch first (cheap fix) and see what happens before letting your independent fix anything. See http://www.benzworld.org/forums/w163-m-class/1166641-ets-bas-warning-light-fix.html?highlight=brake+switch+replacemet for DIY instructions. My 2 cents.

Thanks. Do you know if the brake light switch could also have anything to do with the cruise control not operating? I've seen lots of posts regarding the brake switch but no one else mentions the cruise control. The cruise control stopped working (won't turn on) at the same time (approximately...I obviously did not notice it simulateously) that the BAS/ESP/ETS lights came on.

I do not think that the cruise control is related to the BAS/ESP/ETS lights. It just does not make sense that it would. But I am not 100% on that. And as far as the switch....since it is a $25 item, I am going to replace that first, then if I have too I will get the codes read. I will replace the switch this weekend and post results.

Oh, I found the switch here.

At least I am thinking this is the correct part. Will know for sure once I remove the existing one. :-)

Yes............. a faulty brake switch will affect your cruise control.

I replaced the brake switch today and the BAS/ESP/ETS lights are out. Everything looks like it is back to normal. Just wanted to say thank you for you help.

The part was only $14 at the dealer. Very cheap fix.

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1999 ML430 Black
2004 PT Cruiser

Thank you all MBDOC, WOLFGANG, ML 320, Azinn .......for all the advice

I have the 2002 ML 320 Km 136 000
Here is the problem I have not done much: mostly excuses being; 2 small kids and the fact that my ABS ETC etc and eventually the engine light sensor only comes on when it rains, further complicated by the fact that I just rust protected the vehicle underneath and on 2 occasion despite it raining the above sensor lights did not come (I assume the Rust proof agent acted as a waterproof for a while) I did take a visual observation under the vehicle looking for chaffed wires etc but must admit I could have been more thorough - I was shocked to find the one sensor right rear wheel disconnected ???? - remember the Snap-On "obd" reader gives PO 500 "A" indicating left side fault code (and yes MBDOC and Wolfgang said; take it to Merc so they can run a diagnostic on the proper Merc machine and I think he further stressed that they run scanner on the transmission sensor port), however, the ABS, ETS etc. and eventually the engine light sensor are back on again with the rain and will probably stop illuminating the dash when it dries up again.
But now I have an additional/further problem, doing a one direction 560 Km road trip I had no problem Averaging 125 km/h and using speed cruise control but on the return trip on a perfect dry road with he speed cruise control on the cruise control The Electronic traction stabilizer (ETS) started flashing (thereby automatically disengaging cruise control) and on one or two occasion felt a miss/hesitation, but it was not a engine, plug misfire. Under load or acceleration from 100 km/h and up, the ETS - Electronic traction stabilizer would flash intermittently - there where no other lights illuminated on the dash like when it rains, when I pulled into gas station radio off, window open, I felt and heard a intermittent rubbing/grabbing notice and sound from my left front wheel, upon a roadside visual inspection of rotor and pads for obstruction – none find.
My conclusion, Its not a wheel bearing causing the speed soensor to act up as there is no Whining noice eminating from and when I raised the front of the vehicle there was some play on both front wheels at 3 and 9 position, I assume now that there is a front left speed sensor or wiring problem from this point to the fusebox and is sending error code to the computer telling it that I am loosing traction on the front left wheel and braking as a result but I thought the ETS only engages up to 80 Km/h - if so must be real screwed up sensor

Conclusion I hope to do a better visual inspection for chaffing/short and remove Front left wheel and check under fuse box. And thanks to Nisan for you’re good advice OHM meter check on all three sensors remember the right rear one is disconeected - thank you
My reservation to follow MB DOC wolfgang ..... advice yet: is that it has been my suspicion that a wire/electric problem can take many hours and that the Technicians labour book does not specifically say how many hours, perhaps I should tel merc and find out how much it is to run diagnostics (presumably 1hr labour) and what’s the maximum labour that can be charged after that and lights only come on in rain.
So I think I am going to give it one more stab (do I wish I had the WIS or factory manual now !@#$~#$!#$%!) taking the above into consideration and IF I FAIL recognize defeat and call the MERCEDESE MINT Dealership

I have already replaced brake switch and done reset procedure to no avail. BAS/ESP is still on and dealer says steering angle sensor needs to be replaced for $1500!

Does anyone have any other suggestions besides Vaseline?

Independent tech says no after-market alternative available.

Cheers,
Mark
2000 ML55 - 103K and still going.........

BAS/ESP, ETS, & ABS WARNING LIGHTS COME ON AFTER DRIVING A WHILE, I TURN IT OFF COOLS DOWN AND THEY GO OUT AN THEN AGAIN. I TOOK IT TO RUN A DIAGNOSIS & THE COOLANT TEMPERATURE SENSOR IS FAILING BUT IM NOT SURE THAT WILL WORK.

Replaced battery in my 00' ML 320. BAC/ESP light stayed lit.
Thanks to RRodz for advice on how to re-activate the Steering Angle Sensor.

Cheers

Chris