Veteran Techs
 

Hi Group,
I have a 98 ML 320 with 173k. I've submitted past posts reagrding my ETS/ABS lights coming on intermittently then staying on continuously over this past year. I didn't want to spend the $100 to have the dealer just check it. At first I thought it had something to do with the outside temp as when the light would first go on it was pretty warm, as in the 80's and 90's outside.

Then the light just stayed on last summer. Going off once in a great while, only to come on and stay on again.

This past weekend we had an Arctic blast having temps 5 to 15 below zero. To my JOY the light never came on the first morning I started the ML. Now three days into the blast, they're still off. (it is nice to have abs and ets again!)

With the vast experience of the techs in this group, can the diagnoses be narrowed?
Give me a glimmer of hope!
Thanks in advance,

It's hard to say without running codes , but on and off are most likely the stop lamp switch , they are really common on ML's .

When a computer has a problem you need an expert!

The traction system is computer controlled, you need an expert to read codes from that system..at least 50-60 possibilities for that problem.

Thanks much,

I won't bother with this again!

You might show a little more patience as some of us don't read the forum on a daily basis. My 98 ML320 showed the very same symptoms, with random actuation of the ets, abs light, then more permanent. Not having any cold weather, I couldn't duplicate that part.

My problem turned out to be bad solder joints in the ABS module. Bad solder joints seem to be hereditory with Mercedes, over the years. The joints involved are the leads that feed the ABS pump motor, found just below the windshield washer tank.

The dealers have been known to blame the ABS failure on leaking windshield washer tanks. the module is about $900. Since the printed circuit is fairly well sealed, I doubt this. Maybe your solder joints are conducting better when cold and will become intemittent when hot.

Part of the start up procedure is for the ECM to test the pressure pump so when it doesn't run, it sets the codes and locks out ABS and ETS.

Not withstanding all the above, the PC board can be removed fairly easily after removing the drivers side headlight assembly. 4 torx screws hold the assembly on. Keep things clean as you will be exposing hydraulic pistons.

If you are handy with a VOM, you can verify which joint is open. Personally, I would just resolder both pump motor connections where they land on the PC board. You must remove about 1/4 inch of semi clear sealer to do this.

I have some pictures if anyone is interested in trying this.

Regards,

Jim in Phoenix