Ctrixx

I have a 2007 S550 with roughly 85k miles. Recently the car's computer system has been resetting while I am driving on the highway. The entire command/nav system and even headlights turn off then turn back on as if I was just starting up the car. I also feel a stiffness in my steering wheel as the car is resetting itself. All the while my speedometer/tachometer light cluster and other gauges stay illuminated . On some occasions when the command shuts down my Esp/Abs lights will come on over the dash and then it will recycle itself off. No issues with the engine while driving but this is a very concerning issue. MB Dealership could not find anything.
This all happens at different times while driving. Sometimes it's about 10 or 15 minutes into driving. Mainly it doesn't appear to follow a constant pattern. Sometimes I can drive for an hour with no issues. I have seen a similar situation on YouTube with another owner of a S550. It's like my car has a ghost in it. Someone please HELP ME!
Does anyone know of any similar problems with this vehicle OR any advice?
This is a safety concern for me at the moment. I NEED HELP......... PLEASE HELP!

Mike5215

This is going to sound stupid, but check that both battery terminals are snug. For everything to go dark like that all at once seems like an intermittent connection to power. Worth a shot.

MrRat

Check for water intrusion into the cabin. I would think that the first things the dealer would check is cables/grounding and ensure everything was dry. There has to be some way to monitor what's happening.

The fact that it keeps running may be a clue. Was anything changed or updated, accident damage fixed, or maybe a remote starting system was added at some point?

I found this video of someone with a similar issue, I think it occurs at 2:30 into the video.



This situation may be that one of the devices in the optical ring is dropping out. However it does occur in the rain while turning, so water is a suspect as well. It collects in the underfloor and can flow when either cowl or sunroof drains fail to flow.
Either of these should be leaving a code. It's worthwhile to check if its related to the optical ring, it could be one of those devices or an optical cable or its connector.

Mike5215

I don't think the gauge cluster or headlamps are on the fiber optic ring though.

MrRat

Good point. Is it possible that he lost all power, with a momentary engine stall as well, hence the jerk in the steering as engine power was interrupted?
The engine continued turning at a slower rate than while it was running, sort of like from push starting a car with an automatic transmission.
It then restarts (when the electricity flows) while the rolling car's drivetrain is keeping the engine in motion.

I think we may have lost the OP. There is another thread with the same issue, and the OP disappeared there as well.
https://mbworld.org/forums/s-class-w...e-driving.html
This may be more than an electrical problem.

Mike5215

Maybe he was embarrassed about not checking the terminals first?

w221 2007

I'm having the same issue with my s class. 2007 w221 with almost 110kmiles. The system just shuts off after 3-10minutes of driving.. doesn't shut off again. The computer/command module shuts of immediately without having lights on the tachometer or the screen on after you shut off the engine.. like it really wants to shut off and turns back on like nothing happened at all. I took down to Mercedes and they can't figure out anything with it. Anyone with similar issues that has had it resolved please help.. im losing options to fix this car

GODVET

I have the same problem S550 2007 I didn't have this problem until the dealer change my ICM computer board but i was thinking it could be the battery as well I had the battery store check both battery and the battery i9n the rear was only putting out 11.5v so i'm thinking about replacing that battery before I take it back to the dealer.

CaliBenzDriver

Check your alternator is working normaly to supply 12.6V or better while driving.

Check the battery date to see if over 4.5 years....

Check engine-chassis GND strap integrity
Check both battery connections including GND to chassis

Car loosing power while driving is a serious cause for attention.

Ctrixx

Fix for Gremlin! I know what your issue is. I can save you thousands!

I know what your issue is. I can save you thousands!

TripleDown

Check your ground straps...easily overlooked and they caused a very similar failure on my old volvo 850.