05 E500 Red Battery Visit Workshop Codes 9091, 9051
 

I have an 05 E500 that has a red battery visit workshop message on, when scanned it gives me codes 9091 and 9051. It drives fine, battery never dies, all consumer functions seem to work. I have tried:

1. Swapping relay with known good one.
2. Swapping battery control module with known good one.
3. Swapping polyswitch fuse with known good one.
4. Auxiliary battery was bad so I replaced it.
5. Alternator tested bad so I replaced it with one from Advance Auto Parts.
6. Clearing the codes with a computer, they come back after a few drive cycles.
7. Front pre-fuse f70 (passenger foot well) looks good.

I'm kind of stumped here :nix:. Maybe I need a OEM alternator, has anyone had problems with the Advance Auto Parts ToughOne alternator not communicating the correct information to the battery control module?

Thanks for any help!

Some possible things to “consider”, short of replacing alternator with OEM.

9091 = contact of component K57/2 (Auxiliary battery relay) does not close or the fuse upstream of the contact is defective. Note part # 0025426419 replaced by 0025424719, check condition front pre-fuse f70 (passenger foot well).

9051 = BCM software see attachment and if VIN is included have dealer check to see if service campaign 2005060008 was completed.

The f70 fuse is good.

The service campaign 2005060008 has not been completed but the service writer said he has never seen one that had to have that done. I swapped the battery control module with a module that is working on a 2003 E500 with the same part number and it produced the same error on the 2005 E500 that went away when the part was placed back in the 2003 E500 donor vehicle.

I guess I'll try replacing the relay with an updated relay first and post back.

Interesting 152,949 vehicles affected. Service campaigns do not expire if VMI shows SC applies to your VIN and is outstanding this is a no cost repair covered by MBUSA.

Thanks for all the help konigstiger.

Last 7 of the VIN is A688881 so I know it is part of the service campaign. I went back to the dealer and spoke with a different service writer who told me there were no open campaigns so they would have to charge $80. I guess the first guy just didn't know what he was doing.

I noticed today it also says Active Hdlmp, currently unavailable but both xenon headlights seem to be working fine and are angled correctly.

My best bet is probably purchasing the updated relay at this point correct? They aren't cheap at $140...

Next step, given absence of problems + aux battery replacement, attempt to flash BCM.

Some more information for you. Main battery off is at 12.28 on it's at 14.40, Aux battery off is at 12.57 on it's at 12.56. Does that look right to you? Shouldn't the aux battery be charging when the vehicle is on?

I will schedule an appointment with Mercedes to have it flashed today.

Aux battery is isolated by relay unless system detects low voltage on aux --> charge, or main circuit fails --> emergency use.

12,3V is lowish but if battery discharge current is still high, no problems.

testing batteries is whole science.
Voltage alone can give you head start, but checking voltage under the load is the only reliable test.
Let's see what scan will tell.

The main battery was low, 50%, but it load tested good. The earliest Mercedes can get me in is the 12th so it will be awhile until the bcm is flashed.

When you unplug the main battery isn't the auxiliary battery supposed to power the lights in the trunk? It doesn't...

Aux batter suppose to be for SBC only, but there are rumors that it can be more.
I have not seen official publication that would explain it precisely, but doubt trunk light would classify as emergency.

Absolutely not. If it's the right reman alternator, it will work fine. The reman IS an OEM alternator, just with new guts, most importantly a new voltage regulator. That said, some remans are better than others. Most likely, the Advance one is a from one of the national remanufacturers; maybe not the absolute-best, but it should work fine. I have a Pep Boys reman alternator, probably rebuilt by the same national remanufacturer that remanufactured yours. $139 at the time. Worked great when they put it in, and has ever since. That's basically ten percent of the price of the one from the dealer. If I were doing it today, I would order the Quality Built reman one from Amazon. But it likely isn't the alternator. And you can find out just by taking it to Advance Auto Parts and having them test it, for free. Autozone may do so as well. Instead of just swapping parts, you need a decent Indy mechanic who will tell you what is wrong. If you are near the NY area, I can help with a very good one who works for a very reasonable fee. Others may help you if you give us an idea of where you are.

However, if the battery was low, you can check and see if it's good by taking it to Advance Auto Parts and having them test it with their Midtronics tester. This is exactly the same one they use at the dealer, and the only one that MB recommends.

Figuring this stuff out is more complex than many people think, but usually a hell of a lot less complicated than those on this forum seem to believe. There is no genie at the dealer. Just take it to a good mechanic, the one your friends recommend.

There is at least one thread on this forum that explains it in detail and gives a copy of the training material for mechanics that explains it in even more detail, with diagrams. Edit: I have attached them in a post below.

The aux battery charges only for ten minutes per start of the car.

With all this drama, one appropriate step would be to pull both batteries from the car and just CHARGE each one with an automatic charger on, say, 6 amps, until it shuts off. That's one of the first things I think you should have done. And check the main with a Midtronics tester after doing so (free at Advance Auto Parts). It really could be as simple as a fault in the main battery.

My own view is that fault codes are very helpful, but that's all. They are clues. And we all know that with the W211, electrical system gremlins can defy the ability of that system to try to tell you what is wrong with it. Having experienced what happens on the ML when a couple of cells in the main batt go bad suddenly, you can't expect a logical progression of warning lights, or even accurate warning lights. On the ML, as has been described by other MB owners on here as well, you got every buzzer and warning sounding in a cacophony of sound, and the dash lights were, well, "going crazy" is an accurate description. They didn't just come on or flash in any logical way. Sitting in the driver's seat, all I could do is imagine that the thing was going to fire the airbag into my face if I kept sitting there. And ten seconds before, the car was running magnficiently. Fortunately, because I had read about this, I didn't panic too much. Parked the car and took a taxi to Advance, bought the H8 Platinum battery, and put it in myself, God help me. (Very doable when you use the pry bar method of sliding the battery from its under-the-seat location on the ML, but a lot of exercise nonetheless.) Problem solved instantly.

Amazon has an AC/Delco AGM one (size H8 or Group 49) at a good price.
Walmart has an AGM one for like $139, and it's a good one with a 5-year warranty, and a non-AGM one, also with a 5-year warranty, for about $20 less which will also work just fine. The AGM one: http://www.walmart.com/ip/Platinum-E...ttery/40647529

The Non-AGM one: http://www.walmart.com/ip/EverStart-...ttery/16782659

(Despite the folklore on here, the official MB documents say that either an AGM or a wet battery of the proper size are what the system was designed for. That said, since the thing is in the trunk, the reduced possibility of hydrogen emission by an AGM battery makes it probably-preferable, but I have been running a basic Sears DieHard Gold Group 49 sealed wet battery in my trunk for 3 years and it runs like a champ. If they had had the AGM in stock, I would have chosen it. Today, I would get the AC/Delco or Walmart Platinum if looking for the best value, or the Advance Auto Parts Platinum if looking for maximum convenience; we have the latter one in our ML350 for exactly that reason...it was just a few blocks away and they were running an amazing promotion if you ordered online and picked up in the store, and they will install for free at most stores.)

There is a 2-phase consumer switchoff prior to and during aux operation. Pax compartment lights are switched off in phase 2. Trunk light isn't clear. Nothing will be powered by the aux batt unless the engine is running.

I have attached two documents regarding this system.

I am still trying to make sense out of all those technical bulletins.
Bare with me, I am skilled mechanic and electrics/electronics is something I was forced to learn by situations like that.
So the theory that G1/7 battery is SBC backup is gone. The battery powers whole car when main voltage drops and turning off some electronics will not help.
Then there is theory and real life.
I could not figure out how I had consumer electronics warning coming for a week, when the battery clamp was not tight enough.
It was tight enough to supply hundreds of amps to starter, but I guess not tight enough for computer voltage test.
During those week long vacation I also had Autoscan hook up all the time and it never show undervoltage.
Talk about paranoid computers...

The way I understand it, the AUX is there because of the SBC. It's there to make sure you have brakes when the rest of the electrical system goes haywire. Once they removed SBC, they removed the AUX battery. But being there because of the SBC doesn't mean that it exclusively-powers the SBC.

The brakes need electrical power. Normally, that is provided by the alternator. When the alternator fails or works improperly, the main battery steps in to power the operation of the car, to give you a chance to get to the shop or home, provided that either is fairly close. (When my alternator failed, the car operated absolutely-normally, but electrical power was being provided by the main battery, and I got the red dash warning, whereupon I could see from the voltage monitor that the battery voltage was going DOWN when I pressed the accelerator rather than UP, and I wasn't going to be able to drive for very long. Off to the shop I went.)

As the main voltage drops, the car tries to extend the useful range of life on the main battery by cutting out the consumers in two stages and finally, as a last resort, injects the AUX to the system to make sure you can stop. The AUX battery is powering more than just the brakes at that point (like it's powering the engine ignition, limited transmission shifting, etc.), but its purpose is to make sure you can stop. At the time that it cuts in, because the purpose of the aux battery is to enable you to stop, the dashboard message you get is "STOP THE CAR". Because many people can be expected not to stop exactly that second (i.e. in the middle of a freeway), the AUX should give you something more than just one brake application, but when it gets cut into the system, the car starts telling you to STOP.

When there are electrical system issues, including but potentially other than just alternator issues, the AUX battery stabilizes the electrical system by maintaining the voltage above a certain level, but only when the engine is running and only after the car has tried to stabilize voltage by other means.

But because it's there to make sure you have brakes when the rest of the electrical system goes haywire, it's not going to power the trunk light when you disconnect the main with the engine off. And it's not going to start the car.

However, I can see how "it's for the SBC" got confused with "it just runs the SBC".

05 may not be able to flash bcm. I just went through this whole ordeal on monday and tuesday. Come to find out, something was incorrectly coded in the rear sam.
Question, do you have a factory battery in the vehicle? What are the Amp hours for your battery, most mercedes oem batteries are 95AH. Some actuall values with a sds should be able to decipher exactly what is going on. When you say "known good" what exactly do you mean by that?
Try leaving the ground cable on your battery disconnected for 10 minutes or so.

Like the explanation
I speak 2 language every day and occasionally talk Technics with other person speaking the same 2 languages and still can't make precise conversation.
Human languages have lot to desire precision-wise.
So how about
"The aux battery is there to give the car emergency power needed for SBC"?

:crazy:


I think you are hiding behind the English language to hide your total lack of understanding of MB systems----you have over 19,000 posts over at the dating forum and you still have difficulty with basic wiring diagrams and terminology ----come on--- start to be honest!!!

cmriv:

Yes there is a factory battery in the vehicle. I do not know what the amp hours is on the battery, do you think the auto part store could tell me this? When I typed "known good", I meant I swapped the part with a working identical part # from an 03 E500. I have already disconnected the battery cable for longer then 10 minutes with no change. I tried a brand new battery from autozone in it with no change so I doubt the main battery is the issue.

Thanks for trying to help!

wjcandee:

I'm in Hampton Roads VA, my indy mechanic thinks the bcm needs to be flashed but he doesn't have the equipment to do so.

I have read other threads where the advance voltage regulator when attached to an oem alternator has not communicated properly with the rest of the car and caused the battery light until it was replaced with an oem regulator. I'm assuming advance uses their aftermarket regulator on their alternator which is why I thought it could be the issue.

It has had 2 brand new batteries (aux and main) in it at the same time, I put the original back in because it didn't change anything. Do you still think I should pull both batteries and charge them? I will take it to Advance today and see if the midtronics makes any difference on the test.

Thanks for trying to help

On a scale of 1-10, his english is a zero. spambot :smash::smash::smash::smash::smash::smash::smash:: smash::smash::smash::smash::smash::smash::smash::s mash::smash::smash::smash::smash::smash:

I'll be in that area this weekend. Too bad i don't have a tablet to ride with otherwise i could hook you up in 24 hour mode and see what is going on. However, on your BCM circuit you have the following,
F33-rear pre fuse
G1-battery
G1/7-aux batt
K57/2-additional battery relay
F32-front pre fuse
M1-starter
G2-alternator
X30/6-cockpit voltage distributor (CAN) connector
N10/1-driver side SAM
K75-cutoff relay for incorruptible loads
X30/13-circuit 58D voltage distributor
F34-interior fuse box

Your bcm monitors all these things. IF you are able to flash your bcm, try so. I wasn't able to earlier in the week with a similar issue. If you can't, Your multimeter is your next best step. OHM-ing things out and checking for proper voltage may or may not help. You just need someone familiar with the system to be honest.

Evidently Plutoe's big problem is grief for being ban in all other places.
I don't know what is his deal on this forum. Moderators promised to take care about this clown and he still does that. :smash:
Bad sample spreads like disease.
What he smokes in Florida that he can't even read numbers? I have over 30,000 post on benzworld forum