2015 Mercedes C300- Auxiliary Battery Malfunction with DTC B21DC01

[@VoltageDropDiagnostics]

Check out my amazon affiliate link to help the channel: www.amazon.com/shop/voltagedropdiagnostics

[@djosbun]

PJ has unveiled the next superstar diagnistician.........as long as he listens to his master teacher and absorbs the brilliance!

[@VoltageDropDiagnostics]

He is going to be good. Real good.

[@nathanmurphy2161]

This video just saved us a ton of diag time and more importantly helped out a good customer of ours!

[@VoltageDropDiagnostics]

That’s what I made the video for! I’m so happy to hear that!

[@kennedysgarage3281]

My own E220 has this exact message on instrument cluster intermittently. Which I have been meaning to take a look at ,it may not be the same issue but it is great to see some good test info. Love the videos keep them coming 👍

[@VoltageDropDiagnostics]

Those have real auxiliary batteries, dont they?

[@NewLevelAuto]

You must have a great support team out there somewhere . Great job brother 👍✌

[@VoltageDropDiagnostics]

Id put my support team against anybody else's! That's for sure!

[@caliautotech21]

Nice video as always bro! Nice to have people like you out there to post this type of info to help others!

[@VoltageDropDiagnostics]

Thanks buddy!

[@pjgammarano571]

Hey Pat (and apprentice) - Another thanks to you (both) for this research & deciphering on this auxl battery (Mercedes' misnomer ?) !! People are gonna be checking out this hard-to-find info & demo for many years ! P J G

[@VoltageDropDiagnostics]

Thanks! Im glad that it has helped!

[@TheDisgruntledMechanic]

Thanks for the info! and yes sometimes the information you need can be scarce.

[@VoltageDropDiagnostics]

Yeah. I was surprised with how little info was on all data for the 2015 model year, but the 2014 model year had a ton of info.

[@stevenkietzke5582]

Good to be able to reach out to other techs. Good information thanks

[@VoltageDropDiagnostics]

Yes! Having a solid network is key sometimes.

[@billyyoder8171]

Thank you Patrick. Good job. Have a blessed and safe week.

[@VoltageDropDiagnostics]

Thanks for watching Billy! I hope you have a blessed week as well!

[@kurtkennedy5370]

You are the man! I should have looked this up for you the other day. Nice find and fix!

[@VoltageDropDiagnostics]

No worries man. I was fairly certain about the capacitor being bad. I just hate making calls without being 100% sure.

[@ابراهيمجبران-ن7د]

After changing the battery, does the car need programming?

[@VoltageDropDiagnostics]

Nope. You should be good to go.

[@khalidk12]

No need

[@SuperMarioDiagnostics]

Great video man! Thanks for the shout out!

[@VoltageDropDiagnostics]

You deserved it man! I couldn't even find the capacitor location in SI so I jumped on youtube and who had the first video that I seen for this? My man Mario hahaa

[@RedneckProductions39]

You got me! (I’m the apprentice)

[@VoltageDropDiagnostics]

It wasn't the first time, and it won't be the last! hahaha

[@flatratemaster]

All info on Euro cars is in the factory scan tools🤬

[@VoltageDropDiagnostics]

Yeah, now that I have been using ista for the new Supra, I am learning this. It just sucks when you don't have those scan tools. I don't see a toyota dealer buying an xentry anytime soon haha

[@isalmankhan1]

Thanks for sharing Bro👍 This is a difficult fault to find

[@VoltageDropDiagnostics]

Thanks for watching!

[@loganandmarleyhall4172]

can this affect the power steering ?

[@MrNod56]

What is the location of auxiliary battery in Mercedes c250 year 2015? Thank you

[@VoltageDropDiagnostics]

Should be on the passenger side, behind the carpeting

[@MrNod56]

@@VoltageDropDiagnostics noop, not there 🤷🏻‍♂️

[@zarshedmedia]

Im getting same problem should i buy new or i can still fix it

[@VoltageDropDiagnostics]

buy new. Sorry that I am just getting to these comments.

[@mazenkanso]

Thanks for the video, when I got auxillary battery error, I replaced it and the error was gone but the start/stop stopped working ! again I bought 2 more parts but the eco on the dashboard does not show up. I reset the car using Launch scanner, again it did not resolve the problem.Please can you help

[@silentkilla5339]

I saw that on my screen in my Benz c300 4 matic, is this the reason why the car won’t start?

[@dominikzurawski5429]

Hey, Thx for video, where i can by this module ?

[@dominikzurawski5429]

I have A 205 044 00 73

[@VoltageDropDiagnostics]

@@dominikzurawski5429 i got it directly from the dealer

[@dominikzurawski5429]

@@VoltageDropDiagnostics Thx for info, i have checked fuses and one of them is faulty. I replace that one.

[@dominikzurawski5429]

I meant capacitor not fuse

[@arlokkkk]

Thanks for this video man! I just a message on my c400 saying " auxiliary battery malfunction". So you have the part number that I have to buy by any chance? Thanks

[@prospexican]

great, my customers car has both batteries acting, i did recommend him to replace both batteries and clear the codes and go from there, same code so. i told him 2 days ago that some false codes might come on w low bad batteries.

[@elitegalaxy4042]

How can I get that part I got the same model !!!

[@briankotze57]

Info is appreciated. Keep them coming

[@VoltageDropDiagnostics]

Thanks Brian! I have a good one that I am editing now!

[@promiseofwar]

What’s the cost to fix that?

[@VoltageDropDiagnostics]

I honestly dont remember.

[@kevinbarry71]

Couldn't find any information because; Mercedes

[@VoltageDropDiagnostics]

exactly! haha

[@wyattoneable]

It seems those Germans don't like giving up information. I have first hand experience with Germans, I'm married to one. (ha ha) Great tip.

[@richardcranium5839]

not just the germans. last place i worked sold japanese. was told many times not to give out info(from corporate) my reply was bite me

[@VoltageDropDiagnostics]

This had me dying from laughter!

[@newtongsm]

I went to a exhibition there was a.zf stall.ask them why new 9g tronic gear box use plastic oil pan answer was it is classified

[@jeffmajor1816]

Part #?

[@VoltageDropDiagnostics]

A 205 905 34 14

[@JoelAutomotiveInaction]

great diagnostic , 💪🏻💪🏻

[@VoltageDropDiagnostics]

Thanks Joel!

[@PaulyD0859]

The lack of service info on some makes is maddening! 🤬

[@VoltageDropDiagnostics]

Yeah. This one was frustrating because I knew that the capacitor was a common failure part. It was an easy diag. But gathering up the information to be 100% sure of the failure was a pain in the rear.

[@PaulyD0859]

I wonder sometimes, if the manufacturers believe that will force people back to their dealers. I think, all it really does is piss off people and make them hate those car lines. There are certain car lines I tell people to avoid like the plague and Mercedes are near the top of my list, just for that reason.

[@alexsteven384]

Mines only fails when the temperature is cold... 2 miles later and its OK...? In the summer no problem...

[@angelamartinez5691]

So glad to know this! Thank you.

[@kingsleyjustine8904]

If I make the capacitor swap with a new one, do I need to do something to clear the error message? Great video by the way.

[@VoltageDropDiagnostics]

Kingsley Justine nope. For me the light went out on its own.

[@kingsleyjustine8904]

@@VoltageDropDiagnostics Thx for the quick reply.

[@skillz1855]

Why didn't you simply use a digital volt meter

[@VoltageDropDiagnostics]

Only because i almost never use one. You never really know how a circuit is meant to operate. Sometimes such simple circuits are being pulsed on and off and while using a voltmeter, you can get a reading that doesn’t make sense not knowing that the circuit is being turned on and off

[@vm6971]

Great job on a content for Mercedes! Like!

[@VoltageDropDiagnostics]

Thanks!

[@funtimeswithanaia912]

Thanks much, helped a lot!

[@VoltageDropDiagnostics]

Glad it helped!

[@alexandergrubnik4484]

Good job Sanks for hint

[@VoltageDropDiagnostics]

Thanks for watching!

[@x7royalhbb943]

thanks for sharing

[@VoltageDropDiagnostics]

Thanks for watching!

[@robertmedina6875]

Why people buy Mercedes money pits lol

[@VoltageDropDiagnostics]

Thats a good question! 30,000 miles on this one!

[@angsdoordecorandmore9132]

🖤🖤🖤

[@moebassidji8306]

great info. thanks.

[@VoltageDropDiagnostics]

Thanks!

[@michaelyouens6133]

Iv had my 2014 220 c class for a year and it's the worst car iv ever owned its nearly a weekly thing that something goes wrong with this car everything from ac compressor to main drive belt snapping the list gose on this is the latest problem so once this is fixed it's going and I will stick to bmw !!!!

[@ovwok]

First

[@gbmechanicbellew6124]

Great video. I really like the Diagun 1v . When I checked the link to buy it, it says unavailable on Amazon. Can this not be got anymore?

[@billrimmer5596]

This Mark is high tec

[@VoltageDropDiagnostics]

I just heard that theyre on backorder for about another month! Sorry!