Hi all:
I'm having trouble that I hope the forum can help me with.
My 2007 S550 (Base model) was exhibiting signs that my alternator was failing. The red light in the shape of a battery was illuminating on my display. The battery wasn't charging even though it was only about 2 1/2 years old. It got down to about 11.6 volts if memory serves correctly. Just to be sure it wasn't the battery, I put my battery charger on it thinking it would charge right up. Well, my charger indicated that the battery was not charging. So, I headed on down to Autozone and bought me a brand new battery, excited that it wasn't the alternator.
After installing the new battery, I started the car and the red battery indicator was still illuminated. I tested the old battery with my mulitmeter - full charge (it had been on the charger). As it turns out, the gauge on my battery charger isn't functioning properly. No worries, though, I figured it was the alternator anyway. So, I drive the car around for a couple of days with the red battery indicator on (yeah, I know I shouldn't have) and the battery drained some, then started to overcharge. A few miles after I noticed the battery was starting to overcharge, my ABS/ESP inoperable lights illuminated and steering the car took more effort. I drove straight home (about 5 miles).
Following that episode, I purchased and installed a new alternator. Replacing the alternator on this car is a bit of a pain, but that's for another post. Replacing the alternator required disconnecting the battery, which I did while I was working on the car.
After I replaced the alternator and reconnected the battery, I started the car and I no longer have the red battery indicator illuminated on the display. The battery seems to be charging fine - alternator seems to be doing its job.
Also, immediately after starting the car, I have no ABS/ESP message on the display. However, when I start driving the car, the ABS/ESP inoperable illuminates and steering is more laborious than normal. If I limp along at 5mph or less, the ABS/ESP inoperable message will not illuminate. If I accelerate, however, it will come on and steering gets tough. I can pull over, turn the car off, and start it back up again and the warning lights are off again until I accelerate.
I have a cheap OBD II scanner through my iPhone. It was not picking up any fault codes, so I took the car to O'Reilly Auto Parts. They put it on their scanner and it threw a P0620 code. The guy from O'Reilly asked if I backed up the system memory before I replaced the battery and alternator. I did not (didn't know I needed to). He came to the conclusion that I need to take the car to Mercedes to get it "re-programmed" since I didn't back it up. I'm not sure that's the problem, but it could be.
So, I thought I would post this riddle to the forum to see if you guys know what's wrong with my car. The ABS/ESP warning could be related to the alternator problem, or it could be completely independent. I read that it is possible there is a problem with the wheel speed sensors, but that error wasn't thrown on the O'Reilly scanner. I checked the all the fuses in the two fuse boxes in the engine bay and the two fuse boxes in the front seat (both driver & passenger sides). All fuses tested good with my multimeter. I still need to test the fuses in the trunk. I also did the "turn the steering wheel to the left, wait 2 secs, turn to the right, wait 2 secs, then turn the car off" to try to reset the ABS/ESP message, but that didn't fix the problem.
What do you guys think? Any ideas before I take this thing to the dealer?
Thanks for your help & input.
I'm having trouble that I hope the forum can help me with.
My 2007 S550 (Base model) was exhibiting signs that my alternator was failing. The red light in the shape of a battery was illuminating on my display. The battery wasn't charging even though it was only about 2 1/2 years old. It got down to about 11.6 volts if memory serves correctly. Just to be sure it wasn't the battery, I put my battery charger on it thinking it would charge right up. Well, my charger indicated that the battery was not charging. So, I headed on down to Autozone and bought me a brand new battery, excited that it wasn't the alternator.
After installing the new battery, I started the car and the red battery indicator was still illuminated. I tested the old battery with my mulitmeter - full charge (it had been on the charger). As it turns out, the gauge on my battery charger isn't functioning properly. No worries, though, I figured it was the alternator anyway. So, I drive the car around for a couple of days with the red battery indicator on (yeah, I know I shouldn't have) and the battery drained some, then started to overcharge. A few miles after I noticed the battery was starting to overcharge, my ABS/ESP inoperable lights illuminated and steering the car took more effort. I drove straight home (about 5 miles).
Following that episode, I purchased and installed a new alternator. Replacing the alternator on this car is a bit of a pain, but that's for another post. Replacing the alternator required disconnecting the battery, which I did while I was working on the car.
After I replaced the alternator and reconnected the battery, I started the car and I no longer have the red battery indicator illuminated on the display. The battery seems to be charging fine - alternator seems to be doing its job.
Also, immediately after starting the car, I have no ABS/ESP message on the display. However, when I start driving the car, the ABS/ESP inoperable illuminates and steering is more laborious than normal. If I limp along at 5mph or less, the ABS/ESP inoperable message will not illuminate. If I accelerate, however, it will come on and steering gets tough. I can pull over, turn the car off, and start it back up again and the warning lights are off again until I accelerate.
I have a cheap OBD II scanner through my iPhone. It was not picking up any fault codes, so I took the car to O'Reilly Auto Parts. They put it on their scanner and it threw a P0620 code. The guy from O'Reilly asked if I backed up the system memory before I replaced the battery and alternator. I did not (didn't know I needed to). He came to the conclusion that I need to take the car to Mercedes to get it "re-programmed" since I didn't back it up. I'm not sure that's the problem, but it could be.
So, I thought I would post this riddle to the forum to see if you guys know what's wrong with my car. The ABS/ESP warning could be related to the alternator problem, or it could be completely independent. I read that it is possible there is a problem with the wheel speed sensors, but that error wasn't thrown on the O'Reilly scanner. I checked the all the fuses in the two fuse boxes in the engine bay and the two fuse boxes in the front seat (both driver & passenger sides). All fuses tested good with my multimeter. I still need to test the fuses in the trunk. I also did the "turn the steering wheel to the left, wait 2 secs, turn to the right, wait 2 secs, then turn the car off" to try to reset the ABS/ESP message, but that didn't fix the problem.
What do you guys think? Any ideas before I take this thing to the dealer?
Thanks for your help & input.
