Please help me troubleshoot ABS/ESP problem
 

Hi Gang. I just moved to Puerto Rico and bought an 09 GL-450.

The ABS light is on and with my own U-scan code scanner, I'm getting code P0721 Output shaft speed sensor circuit range/performance.

However, when the local Mercedes tech hooks up his scanner, he gets around 10 codes. I wasn't able to write them down, but with a quick glance, it appears that pretty much all of the wheel speed sensors are showing a fault, as well as possibly the ABS pump.? Unfortunately, this guy doesn't speak much English and I hardly speak any Espanol. He's already talking about how this might be a $3500 repair if I have to replace the ABS pump.

Before I leave it with him and/or the one and only MB dealer down here, I wanted to see what y'all suggested.

Is there a particular component that would be causing all 4 wheel speed sensors to show a fault?

As for driveability, if I clear the code with my U-scan, it drives fine for a while. Eventually though, the transmission will stop shifting and will just stay stuck in whatever gear it's in. Then, if I shut off the car and clear the codes, it will drive fine again.

it could be a few things. you should really try to get the list of all the codes stored.

btw, i would be concerned about driving a gl in pr... and it has nothing to do with reliability... just my 2 cents

Whats wrong with driving a gl in pr. Ie the guy going to get mugged lol seems like a very prejudice comment about pr and the people there just my two cents

Prejudice? Lol. You have no idea... more like postjudice...

Wheel sensors fail in High Humidity
 

Hey Jack,
If you are having trouble with ABS codes, Mercedes issued a service directive for GL & ML prior to mid 2010. They failed in high humidity, so when one failed, the dealers in PR and South Florida were directed to replace all sensors with an improved version. If yours were never replaced, that could be the problem.