Benz4kids

Hi all, new to the forum but not the concept as I have solved many a problem with other vehicles using forums. Recently bought a used GL550 for the wife to haul my kids around. Since purchased a few months ao, the ESP and sometimes the cruise control are unavailable. I read that it can be voltage, checked alternator at got 14.4 volts output. Replaced the battery, (that was fun) and still I get the light. Short of taking it to the stealer, and other ideas?

Thanks...

Fourdiesel

The cruise control is designed to turn OFF if the ESP system is not functioning for any reason. That could be why you don't have cruise control.
I have experienced instances where, if I hydroplane on the freeway in the rain so that one wheel goes a different speed than the others, true ESP kicks on and the cruise turns off.
The same effect can happen without rain if you have a bad wheel speed sensor so the ESP computer THINKS the speed is different. Therefore, check the function of all the wheel speed sensors.

Benz4kids

Thanks that is worth checking but now ever since I replaced the battery we have a whole new set of electrical bugs. Now the GL won't come out of park or go into gear without multiple attempts. The aftermarket k40 radar detector beeps at random times but seems correlated to the ESP light coming on which is now much more frequent. The lights are flashing as well. Seems I've made the problem worse. Voltage regulator maybe? I'm about to take it to the stealer...

Anyone have any ideas before I do?

N_Jay

Did you replace the back-up battery?

garymporter

My 2009 GL550 did the same thing when I had to drive it a couple of days on the spare tire, which for some reason is a radically different size than the 21-inch Pirelli's. I panicked--it felt like the engine was turning on and off as I drove 70 MPH on the freeway.

I consulted the manual when I got home and discovered, as fourdiesel writes above, that any time ESP detects a variance in tire speed the cruise control will turn off. The manual suggested that you reduce your speed to avoid the problem, and I found if I kept the car below 65 MPH it did fine.

I'm no mechanic, but have you checked your tire pressure lately? It could be something as simple as that.

I've had electrical problems after changing the battery on every car I've owned since the 1990's. It's a pain in the neck.Nothing as severe as what you list, however.

alx

Your car needs to be read...

Benz4kids

I didn't replace the backup battery. I put a trickle charger on the posts under the hood while I changed the battery to make sure nothing lost voltage while I swapped batteries. What's up with the backup battery? I don't even know where it is.

N_Jay

It is in the same box as the main battery.


There are some good posts, do a search.

Fourdiesel

The function of the auxiliary battery is to make sure the PARK solenoid engages. That is it. If the aux battery is going bad the bat. symbol on the display will be white, not red (or the other way around - I'm not sure which)

wchai

You might want to check out this link regarding steering angle sensor: https://mbworld.org/forums/w211-amg/...ensor-sas.html. I just completed this fix on my 2008 E550 the other day and it worked. My ESP light was on and cruise control was inoperative. The fix was very easy as long as you have the proper tools.


I think the same fix would also apply to GL because we also have steering angle sensor. I would clean the SAS before buying parts or doing anything else because this is free.