I have just had the Right hand parking lamp warning thrown up on the dash, on inspection it seems the light is completely out with all other bulbs within the unit working fine, ( including the led dipped beam). The led light that is no longer working is refered to as the parking lamp but here in the UK this light is used for side lights and drl. I've read that the fault could be with the led control module situated on the underside of the headlamp, my question is if that unit were faulty would it normally affect the dipped led light too ? If so could this be pointing to a fault with the side light / drl led itself. Unlikely but possible I suppose? Ive had my icarsoft code reader on the car but both left and right headlamps report no fault codes. Short of removing the bumper and swapping left and right control modules to diagnose further are there any other obvious things I could try before I dive in ?
Thanks

 

Your facelift parking light LED has a dash error but iCarsoft finds no code in module.

You want to figure what part to buy without removing the HL if at all possible. For that use your scanner menus troubleshooting commands.


LED ballast driver out


solderless connections


gaps before soldering


after soldering

Low voltage drop connections regardless of PWM: high current spikes minimized.

You don't have to repair your module. You can replace it with another unit and have it coded to your car LED... a pretty involved process using a barcode reader to pick up the LED S/N Codes

I don't know if a used ballast can be transfered in without recoding it

​​​​​​From glancing over the circuit board I did not see output MOS-FET drivers transistors like inside our KeylessGo module.

If unit shows traces of HL water: it's unrepairable afterwards. Act before water gets in...

> Basic counter measures :
To save these ballast modules you can consider:
1-- Seal HL rear harness connector with RT Silicone.

2-- Weatherize the ballast PCB with conformal coating to protect against wet condensation.


Shown above is our passenger side... later today I shall meet with my driver side ballast while doing front pads/rotors.


Lots of fun 🙄

Pretty easy access through the plastic wheel well cover. Couple plastic snaps and long screws under. All plastic belly pans stay put.

 

Thank you for the information and very useful pictures, I'll try to get the module out, open it up and inspect it. Do you think it's quite possible to have half the board faulty and other areas working fine then ? I assume the single module looks after both the led sidelight/drl and the dipped beam led too ?

 

Yes, this module manages power distribution inside the whole HL. It's a power converter. It gets +12V DC and vonverts that into a hand full of distinct channels connected to each individual HL device with various voltage and PWM.
The microcontroller board also synchronizes both sides HL over data connection.


Many things can require service or replacement of LED Headlights:
1- the harness connections are oxidized... "deOxit" chemical cleaner!

2- the module has internal failure... new module!

3- the HL LED's have burned... new HL!

4- Combination of oxidized module pin has over powered and burned LED: everything must go!


It's important to understand what has happened to have a chance of fixing issues such that it won't fail again anytime soon.

Troubleshoot using the scanner to figure what the smart module reports regarding the condition of its multiple channels.
Armed with this information then perhaps spend couple hours sorting if its module or burned LED.

LED are extremely fragile electrically... so easy to toast that if the LED test bad now, the ballast killed it: "everything must go" outcome!


> Practically...
Let's see what can be done to prevent a big tab:

-- Buy a used controller module and try to code it by migrating data from old to new/used ballast. Launch Elite I believe can do that, double-check.

-- Swapping left to right side modules... takes a lot of time and may create 2x bad headlights


> Driver side HL module review:

solderless pins


module power leads


OMG... ouch!!


other pin oxidized to...


PREVENTIVELY soldered and coated circuit


basic heatsink paste


Hidden MOSFETS or twin diodes
Located under the main connector to prevent removal for quick repairs.
The circuit uses no less than 8x IC chips to chop DC power with high-efficiency.
There is no real hot-chip that requires cooling asside from the main LED-junction itself.
The controller is low-heat design despite heavy heatsink.


PN#: A212-900-8224 by Continental.

 

Get data card for your car and show Cali the variant of the headlight.
So many different types.

 

Master Surya, I can report without equivocation the power pins of this basic LED HL module definitely need poor contact protection before they decide to burn up from high resistance.


vented HL... oxidized connection

A coat of contact lube should protect well against black oxidation developing.

I remember you've shown us how the open venting can introduce high condensation. I have seen visible water inside my HL.

Now we can see how the HL connections in this design can not tolerate well high moisture environments.


All of this is besides the amazing "solderless pins" that cause poor connections by themselves.
Of course no code!

 

Someday I will have to inspect it like you did ....
And solder those push pins

 

Prepare your itchy hands Surya. I have a gem prize for you.

It's easy to work on and should be coming your way when I can drive it more for review.

It's the ESP module, a CAN-C VIP by Bosch...
4 long screws and its out on your clean bench ✌️


So far I noticed improvements of tranny response as well as steering rack behavior and smoother managed brakes (before replacing both front/rear).

I can definitely spot radical CAN improvements that lead me to believe marginal networking needs fixing just like painted GND and the WTF main strap.

Unfortunately CAN-C directly affects engine timings either way according to current condition. That means ECU depends on CAN-C data timeliness.

Our best interest is to minimize factors that introduce timing jitter in this sofisticated system.

We can not change the firmware code but we can tweak chaos out of it.

 

Cali wrote :
It's the ESP module, a CAN-C VIP by Bosch...
4 long screws and its out on your clean bench ✌️

I thought the plastic cover of ABS computer is glued and not with bolts...right ?
The 4 bolts are to remove the ABS computer plastic body from hydraulic module.

Please start a new thread for us to learn..... lots of photos please. Thank you.
I agree, ABS can wreck havoc on driving smoothness for throttle modulation and/or power too.
In fact in my friend's W204 2010 his ABS is now sometime producing those famous fault code ( I forgot the number ), like once or twice per year and if the DTC pops out,
the power steering ( hydraulic ) assist gets cut off too. All he need to do is engine OFF and start engine again and all back to normal.
I tried cleaning the connector, that is all I did, nothing else I can do and since the DTC pops out so very rare..... I made no progress.

 

Surya, your friend is lucky to have you deploy skills to fix his random issue but should his brakes fail after you did a surgical repair on his ABS module, he would no longer be friendly.
That's why I don't mind experimenting advanced solderless remediations on my own chassis.

​​​​​Meaning I show these great modules benefit from improvements but just like for "oil solenoid MOD": I don't encourage anyone to follow suit.


If I have learned something about this chassis is the CAN Bus quietly spreads marginal performance to module under wrap: no code + no good.

Do not dream that no code means no problem. Unfortunately the best bugs are quiet.

I am super impressed that ESP can work at all through degraded conditions. The flip-side is I can see the difference when solderless modules are enhanced compared factory stock .


I am not interested to have my chassis compete with KIA or FIAT. I want my Mercedes chassis reliable without struggling to unlock doors or apply brakes.


So yes I can fix my slow solderless ESP but do you want to get your hands in someone else's brake controller that could suffer afterwards from unrelated dangerous conditions???

Fixing wipers is one thing but brakes involves safety.

​​​​​​The ABS/ESP controller is enclosed in a fancy plastic topped with a metal cover that's glued on by simple RTV. It's not enclosed by melted plastic

There are limits to what can be done. 95 % chance it's the loose pins delivering chaos on schedule.

This module is not subject to any wet environments like SAMS. Poor connections do oxidize that's why we solder them.

This ESP Module is quite repair friendly unlike the skinny ISM tranny shifter.

A strong soldering iron is advised to deal with GND planes.

 

There supposedly an ABS repair workshop in my city. I would probably use their service for my friend's C200.
I told my friend it is either that repair shop or buy new computer side of the ABS, when and if the DTC-s are permanent.
Such intermittent but rare occurring and and many months between DTC is such a drag to troubleshoot.

 

For your friend's C200, the root cause of his problem is not the obvious ESP!

When my W212 was new, twice a month the dash would greet me with "ESP Inoperative..." warnings.

Both Factory + Extended warranties expired with no fix from the best "factory trained specialists" - All I got was resets and "could not reproduce"... amazing struggle.

These are external COM issues. An external network issue in the gateway getting upset by radars or MFK.
The gateway bugs ESP because itself got flooded by other module poor COM'S.

So a wet BlindSpot module causes COM's traffic jam that proove to be overwhelming for gateway and ultimately ESP.

Careful troubleshooting is needed before throwing money at these time sensitive modules.

For your friend, I would cover the basics first: low voltage + Painted GND then scan the chassis for stored transients faults (Blindspots, SGR, F-SAM,...).


On the other end, the poor connections forced by solderless pushes modules right to the edge ready to get upset with little margin. I dislike this chaos so I simply solder electronics for superior networking speed on CAN-C/B.
I have evidenced the engine/tranny/steering/brakes performance are directly affected by loose pins modules on CAN-C without any fault code.

Funny thing is this chaos is well organized as the ECU/TCU/F-SAM/LPFP themselves do not rely on loose pins to prevent limp-modes.

The troublemakers stressing CGW are ESP/SCM/ISM/EIS/R-SAM/... I am overwhelmed how soldering these great modules has transformed my chassis with luxury car performance.

• My engine is super torquee and smooth
• My tranny is seemless, not banging gears
• My steering is biased on 0° center track
• My brakes are touchy and strong
• Never mind KeylessG/DCU now reliable
• Battery no longer drains in days

These state of the art German electronic modules are designed to silently *not* deliver normal performance but restricted to basic service level.

At this stage my chassis has normal voltage, normal oil pressure and normal networking: PRICELESS.
Many thanks to you MS! for our advanced diving discoveries.

 

Ok noted Cali on the CAN BUS could be the actual ESP/ABS culprit.
Lets wait till the ABS/ESP really goes total banana hehehehehe

 

Actually things are a bit more twisted!
It's important to realize ESP fault is not the root cause but only a consequence.

Another unstable solderless module is stuttering traffic that overwhelms CGW/Gateway that forces ESP to error out. Replacing new ESP would not change anything here. The underlaying condition needs to be improved for ESP to work.

So to help your C200 friend, scan the whole chassis for all faults including transients glitches from zombies.

Then we'll make a short list of amazing modules that are built marginally operational: KeylessG, SCM, EIS, DCU, AAC, ISM, ESP, MFK,


Poor GND + Solderless = reliable chaos

When CAN disruption is bad enough ECU/TCU go into limp-mode until restarted.
Weekly or Bi-monthly reboots help by temporarily clearing sleepless CGW backlogged stacks.

When enough solderless chaos is canceled THEN CHASSIS PERFORMANCE REALLY SOARS. Unfortunately this is incremental because anything upsetting the gateway directly upset top VIP's: engine, tranny, steering and brakes.

I don't think you'll want to invest that much time in fixing someone else's chassis for free before yours is in great shape.

 

Cali wrote :
I don't think you'll want to invest that much time in fixing someone else's chassis for free before yours is in great shape.

The free $$ is OK, the true love from me is not there for that C200. because it is not super well maintained like my E400.
Mechanically I will do a job as good as I can do, if I ever touched a friend's car...but with curse and swearing
I don't like working on cars where my hand get dirty from oil stain because engine is not as clean as mine. I am a choosy azz-H now .

 

I totally agree greasy neglected engines are not favorites.

​​​​​​Soldering the ESP will definitely make the engine/tranny run better BUT may not fix remote upsets. Any CAN improvements helps the performance of related modules.

 

Get data card for your car and show Cali the variant of the headlight.

 

Just replying to this to follow up / close the loop, I have had to removed the bumper today to fit a new ac condenser so thought I would diagnose the led issue at the same time, removed both headlights swaped modules and turned on side lights. The problem switched sides and followed the bad module.

I'm now in the process of getting over the pain that a new module is going to cost me around £450 from the main dealer. Any advise on getting this at a lower price would greatly be appreciated, I'm sure the fix on the old module wouldn't be that hard im just not sure I want to now spend the time digging in to that.

 

You should contact @benzninja
to code the module replacement to your chassis.

 

A question for @BenzNinja if I were to find an identical module ( and I mean identical) same part number, same hw and sw numbers so in every way the same part, assuming the module is in good working order, would coding still be necessary?

 

the Led module no
The main module sometimes not if lucky sometimes yes
if you have ILS+ activated 99% yes

this if from the same donor car of course

 

Ok so I don't think I have the ils plus system. Would it help if I did match the exact module part numbers or would one of the new part numbers that has replaced a212 900 82 24 work just as well ? @BenzNinja I can see you offer software to do coding, is this something i could do myself ? Another question I have is does the part have to be brand new or could I code a genuine part that has been previously coded ?

 

just buy a used one from ebay
same as in there and same donor car

 

Just to wrap this thread up with a final update. I had to have the front bumper off to replace a corroded ac condenser, while it was off I swapped the headlamp led modules over which proved out that the headlamp was good and it was indeed a faulty module, I then decided to look for an exact part number, including the firmware revision numbers. I did this rather than trying to buy a newer revised part number from Mercedes as I think this may have then needed coding.

I found an exact matching module from a breakers off a car of the same age ( I known this is a risk as it too could be close to failure) it was 1/3 of the price of a new one from Mercedes, it went straight on and worked, no coding required.

A few months in and it's all still working perfectly, so far the gamble of replacing with a used one has paid off.