2008 ML320 CDI - 119,700 miles.
The brake wear warning light is "manifesting" it self on our dash. I thought it meant the servicing of our brakes was imminent. However, the tech from our tire service location, where we just bought a full set of new tires, said the pads and rotors were fine. When I mentioned I was concerned he was a little surprised and said there is plenty of wear left, well beyond specs. He speculated there may be a sensor that is operating without need.
Is there a way to disable the brake wear dash indicator, or disable the sensor?

Generally speaking I let the landscape guy give me advice on how to manage my investments...NOT.

Similarly, I don't take vehicle maintenance advice from "technicians" at a tire store.

The best suggestion I can make is to get a second opinion. (Disabling a safety feature isn't the smart option here.) Most dealers will perform a "courtesy inspection" for free, and they'll probably wash the car for you, too, while you enjoy a cup of decent coffee. If they come back and say the brakes are fine, then you have cause to start worrying about a malfunctioning alert system, but still not a valid reason to disable it.

Alternatively, take it to a good indie and have him inspect the brakes. Usually they won't charge much for that basic inspection, and if there is an issue and you pay him to fix it, he'll waive the inspection charge.

Or, of course, do a little investigative work in your driveway.

Good luck.

The break wear indicator gives plenty of warning when the pads are wearing down, however it is possible for them to give a false reading. They are just insulated wires that are inserted into the brake pads. when the pad wears down enough the tip of the wire contacts the disk creating a circuit that sets off the warning. When mine started warning, I checked the pads and confirmed that they would go awhile. I just clipped the sensor wire on the most worn down pad which stopped the warning, and ordered the new pads and sensors.

Some have had warnings on nearly new pads. It is not clear whether they re-used an old sensor or had a defective sensor wire, but if the insulation on the sensor wire fails you could get current flowing into the semi-metalic pad which would likely set off a premature warning.

__________________
'97 E 300 D

Not knowing, if or if not the pads are worn down to the sensor, I would suggest a close inspection of the senor wire. As nelbur already pointed out, in some cases the insulation can wear and close the circuit by touching other conductive materials. This can happen if the wire isn't routed correctly and may touch moving parts during every day driving until it is blank wire..

I had an intermittant flash of my warning indicator and it turned out to be a blank wire!

__________________
Mostly, I don't know notin, I just know where to look.
I am looking back, to over 30 years in Electronics Design.
Electrons don't care if they move in a car, computer or relay!

95 W124 E320 M104.992 - Because, I love to repair, naaaah!
Over 221,000 Miles
Cheers,
Norbert

It is possible the light might also indicate brake fluid level. You would have to see what the owners manual says about it.

__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

Thank you,
The pads and rotors have been inspected by a very competent tech and he was surprised I asked him about them. I have a reasonable ability to assess wear and I can see the pads and rotors looked like they had plenty of wear left. A second, and experienced, opinion was reassuring. Adding to the reassurance, the brakes work as competently as ever and I have sensed no loss of braking safety. He pointed out that the pad and rotor thicknesses were well within specs for this vehicle. This tech could have suggested a brake job, he didn't, and I would have had to request him to do the work. He reluctantly gave me an estimate but said it could be outdated by the time I actually needed the work. I feel comfortable that we are OK.
However, the suggestion to check the fluid level is something I did not consider because the dash indicator was for "Break Wear".

Stop at your local MB dealer and ask the parts guy to print out a copy of LI54.18-P-050302. It details the fix for your problem. They probably stock the parts and I doubt it will cost you more than $30-40.

I replace my pads BEFORE they wear down to the point where they damage the rotors. And I don't get around to doing this right this second...

So by the time I get the parts and get around to doing the work, it is time! (They know us driver's don't necessarily get things done right away...)