Otto

this happens to my heated seats when I started my car this morning but it works perfectly.

clembo

It looks like this topic has generated a lot of comment. Thanks for the battery advice, I had no idea that the electrical system was this complex.

e500, Thanks for the heads-up on the switch, I'll call my dealer.

Yesterday was the first time that I noticed my heated seat lights bliknking, I'm glad the a couple other cars had this happen as well. It must have been due to the extreme cold yesterday.

nyca

does the flickering of the LED stop after a while, or is it continuous?

what is the answer here, does the car need a bigger battery? or does the software need to have a higher threshold before deciding the battery needs all available juice for charging, and thus affects accessory use?

patrick

Blinking means function temporarily not available (due to the need of the main battery to be charged).

nyca

how can the system measure the charge level in the battery? With the alternator running properly, its putting the necessary 14-15V across the battery needed to drive the charge cycle, but it can't really measure that charging effect inside the battery. Does it simply have some pre-measured amount of time that it feels it must allow the charge cycle to take place without hinderance of accessories?

patrick

It should stop after a while.

The car does not need a bigger battery. If something drains the battery while standing still (electrical failure) or the owner just drives short trips, the "electrical consumers switched off"-phase will just happen more and last longer (I guess everybody will understand that if there is a failure that drains the battery that much that the car does not start, this system cannot help anumore).

The car always manages to have a well charged battery (also for SBC: safety), but as the maximum consommation of current is limited, it temporarily switches off certain electrical consumers when necessary.

Systems than can be temporarily not available:
(first step)
heated rear window (or how is it called in English)
memory functions
heater vent reduced to maximum 69%
headlight washer system
heated seats
passenger seat position settings (cannot explain in correct English)
heated stearing wheel
and some other functions I do not know how they are called in English

If the battery still does not get charged enough, a second step may begin, then following functions may also be temporarily not available:
Parktronic
remote trunk closing (or whatever it is called in English, maybe you will understand me)
heated front window washer nozzles
heater vent reduced to maximum 53%
heated mirrors
interior lights
and again some other functions I do not know how they are called in English

If this still does not work, there is something going on (battery defective, alternator defective,...) then red messages will appear and the auxiliary battery may be getting involved.

patrick

(I hope this is correct English, but:...) Tension (or voltage) is not current (or Amps)!!!!

But the battery control module measures permanently the charging voltage and (!) current and is able to check the interior resistance of the main battery. In the battery control module is programmed how the battery should behave in certain V/A-circumstances (I am sorry, but as this is getting rather technical my English is not good enough to tell what I really want to explain), MB calls it "bufferalgorythmus".
This, together with the time, can make the battery control module "know" if the battery is defective (e.g. after having been driving for a certain amount of time with the second step "electrical consumers switched off" and the main battery still not getting charged enough).

nyca

no, it makes sense, the ability of this MB system to measure that interior battery resistance is far and above what most "normal" cars can do; that is, if they don't see 14V coming out of the alternator, what we americans know of as the ALT warning light comes on. That aside, if the battery is bad/dead, the car just won't start.

with this kind of system, will this car actually be able to say BATTERY IS BAD as a diagnostic message to the driver when it detects that the alternator is running, yet the battery does not appear to be holding the charge? that would be pretty good.

Bearded Bandit

i had that happen once last week with the stereo screen not working until the car warmed up. has anyone brought to attention to the dealer and what was their response

nyca

it sounds like the system is working as designed from what patrick is saying.

patrick

Ehm,...just one more little detail, if your car has the heated steering wheel option and the VIN number is between 219405 and 380430, it may be possible that the steering wheel heating does not work anymore at lower temperatures due to a faulty heated steering wheel control unit. Units marked with "Q6" are good.

grt62

I'm picking up my new e500 this Thursday, in upstate NY, where it's not supposed to get above zero (lows will be going down to -20 after dark). What should I expect, as I won't be getting home until after dark? Also, I ordered the heating package. Will this likely be one of the faulty units? I don't get the VIN until tomorrow, when my insurance company gets contacted. Fortunately, my garage usually stays about 40 degrees, so Friday shouldn't be a problem.

alewifebp

Well I had it happen again this morning. Cold weather this morning (probably about 10 F), and I hear the static and can't change the volume or turn it off. Drove it for a few minutes, warmed it up, and it went back to normal operation.

jtc3

I had the "car too low" message when it was around 0 degrees, interstingly enought my dealer told me this may happen when I took delivery last March. I also had another cold weather gremlin: while driving yesterday in about 10 degree weather I hit the headlamp wash as there was plenty of sand/salt spray on the car. Both headlight washers froze in the open position until this AM when the weather warmed up.

No damage or anything but since the washers are probably most likely to be used during cold weather I would expect them to work better. German winters are colder than ours here in NY.