a2j

Issue started 3-4 weeks ago. My wife said red battery light flashed couple of times while she was driving. ABS, and some other lights came on and off. Later that day I test drove a GL, no issues. Left vehicle for 3-4 days on a drive way, could not start. Battery had no power. Charged it. Drove for a week without any issues. Driving back home last night, battery light flashing once in a while (red) and front parking sensors beep and flash as often as the battery light. I checked the voltage multiple times, with engine running voltage 13.5-14v. With engine off, 11.5-12v. From my previous experience with red battery light, it was the alternator that was not working. But the light would stay ON all the time. It this case its just flashes at random and so do front parking sensors. Any ideas?

bselph

I didn't sleep at a Holiday Inn last night but would submit that if you are getting the proper voltage reading with the engine running, it is not the alternator. With the engine off and the battery reads less than 12v, I would guess it is time for a new battery.

alx

your battery is bad or you have (less likely in your case) intermittent charging problems.

you should have 14.3-14.7v in the engineering menu with the engine running

if you battery is 3 years or older i would suspect it

a2j

Yesterday, during our 2 hour drive, parking sensors beeped/flashed 10-15 times. I don't even know if this is a separate issue or not. Battery light flashed 2 times but this time it stayed on for 2-3 sec. And "BRAKE" light flashed 2 times for a very short time (I almost did not notice). I hope that battery just needs to be replaced because that's relatively easy fix vs some random electrical issues. Once I got home, I checked the voltage right after shutting off the engine. Interior lights and radio was on. Voltage was quickly dropping from 12.5v to 11.8

alx

the esp and abs will malfunction as observed when the battery is weak/ going bad.

voltage should not drop below 12 volts at any point under your condition (lights and radio). it might drop a bit if you have the rear defrost or lighter engaged, but still really should not be dip below 12 volts even after 15 minutes of running said accessories.

replace battery and take it from there

sak335

I don't know where you are located, but most auto parts stores in North America will load test a battery for you if you bring it in to them. What you describe sounds like a battery issue to me, but charging problems can be tricky.

I'm not one to throw parts at anything. Have the battery tested before you buy a new one. I once chased a charging issue on a BMW M3 that ended up being a loose bolt between the alternator, the charging point on the firewall, and the battery cable. Took me months to figure it out because it was intermittent.

a2j

Well, they could not test the battery while it was in the vehicle. Something was not working or not connecting. So I figured that if I will take the battery out, I might as well put a new one in. So I replaced the battery last night. Will drive for a few hours today, see of battery light is back. But parking sensors still beep and flash. So this could be a different issue that started at the same time.

alx

different issue.

give couple bangs to each sensor with bottom of fist. gently. dont worry. "bumper" is your clue here

if that doesnt fix it - clean them carefully (from outside) with soap and water.

if that doesnt fix it- you need to replace your sensor harness. fairly easy.

a2j

Engine starts better now when its cold outside, with new battery. But, the original issue is still there. What other equipment is located around the battery, under the seat?

alx

What is your voltage at rest? What about when running and driving around?

a2j

I'll check for voltage later today. I just wanted to add that all these issues are happening while driving. Never while just standing, idling. Also noticed a quick flash of a command screen, only noticeable when its dark outside. But it is more rare, just like 'brake' light.

a2j

Today vehicle went crazy. All the lights and beeps at the same time. Parking sensors, battery light, brake light, DSR, SOS, interior lights, seat heaters, headlights, head unit/screen. All restart, beep and/or flash. Some times several times in a row, sometimes 5-10 mins in between. Vehicle is derivable, but I don't feel like driving it. Battery voltage is 13.x right after engine shut off.

a2j

Sounds like this issue:
http://www.benzworld.org/forums/w251...-icon-red.html

I'm also thinking about checking my alternator again, that was rebuild couple of months ago.

a2j

Another update about voltage while driving. It varies from 13.6v to 14.2v From a 20 min driving last week, ~70% of the time it was at 13.7v, ~25% it was at 14.1v and other 5% it was in that range mentioned above but would not stay there for long (more than a couple of seconds). Is this how alternator should work? Shouldn't it be at the same voltage all the time. Engine speed or amount electric devices turned ON did not seem to have an effect on voltage readings. Battery light would flash while voltage was above or below 14v.

edit: Also turn signals would not work while battery light is ON (with or without any additional lights mentioned previously in the thread).

a2j

I took the front SAM out to take a look as corrosion or other visible issues and found none. My next step would be taking to a stealership. This is my final option when I'm out of options. I really don't want to do this, based on my previous experiences going to a local MB dealer. I'm also considering getting MB Star C4 Diagnostics. Would this solve or at least point me in the right direction? Is there a benefit of taking a car to a dealer vs having access to MB Star Diagnostics? I just want my GL running again. But with little dealer BS as possible.

a2j

Running out of time and options. Used MB roadside assistance to tow it to the dealer yesterday. Waiting what they will tell me. Wondering if it'll cost me all my life savings or just half.

alx

alternator... ?

voltage should not fluctuate by more than 0.1-0.3 volts with engine running. if you turn on a large consumer (say rear defrost) voltage should dip for a second but then should climb over 13 volts and stay there. ideally over 14 volts.

a2j

When vehicle was towed to the dealer, it was not even starting. Even with a fully charged battery. I'm pretty sure this is not alternator issue.

But anyway, dealer says it front SAM. $500 part. It will cost me $1200 for diagnostics, labor, part, programming, tax, etc...
Money saved on fuel will be spent on repairs. Why didn't I buy Toyota?

a2j

Another update. Technician found more faulty, corroded electrical connections and modules in the rear. Some liquid got there (he says windshield washer possibly) and not sure how did it get there. Anyway, they will keep the car for another week and total price now 3x the original quote. Those electrical parts are not cheap.

But they were able to find me a loaner for now. 2014 CLS550 4matic.

a2j

So, 3 weeks later I have my suv back. Total bill was at $3600. I even got my broken parts back. Maybe I can send some of the electrical modules for cleaning and rebuild. It is nice to have a fully functioning vehicle back. I didn't mind paying that much for repairs as I bought it for $14k below its kbb value. I just hope nothing like that will happened again. And I don't have enough info/evidence to blame MB for this issue.

alx

I just dealt with an insurance claim gl. Corrosion in front sam, ignition module, fuse box. It was a flood vehicle, but had a clean title. Just sayin

a2j

Yep, flood vehicle was one of the theories. But so far, I was not able to find any evidence to support that, other than some liquid in one area. And that liquid wasn't fresh or salt water.

mrchris

I think I remember reading somewhere about a handful of GL's with bad drains in the sunroof causing some issues. I also had a buddy who's Highlander got hit in the rear quarter and the body shop that did the repairs didn't fix the damaged hose for the rear window washer and it leaked all over in between the sheet metal and interior lining.

Lot's and lots of flood damaged cars out of hurricane areas many of which had their titles washed in a way to avoid obvious records and someone doing a really good cleanup job could cover it up well.

These things have a few common electrical annoyances but corroded SAM's seems pretty rare without a causitive liquid involved.

a2j

Well, the vehicle was not from the hurricane or flood zone. It was inspected by multiple people and none were able to find any traces of flood or that the vehicle was ever in accident. And, of course, the VIN report has none of that also. But the front SAM was actually not corroded, or at least there is no visual issues with it. In my previous posts I've mentioned that I was looking at the front SAM and suspecting that somehow I damaged it. But I'm not sure about that. The corrosion was in the rear, under the spare wheel. Its not that close to the sunroof.
All of this is just guessing and I think I will never know how it actually happened.

mrchris

You might not never know, but I will say with regards to a leaky sunroof, water will get in the headliner and then travel to the rear pretty easy, had this happen on a Jeep I had. Had a plasticky type headliner, water was pooling up at the back of the sunroof and uphill or accelerating it would slosh to the back and drain.