S-Prihadi

Gang,

Mine is a 7Speed Plus version with paddle shifter and the blue tranny oil.

I was fortunate when the trouble intermittently occuring and getting worse at the end of the 45ish minutes drive-on-Sunday-for-fun routine, I had my camera recording the instrument cluster for
voltage + amperage monitoring reason on this thread : https://mbworld.org/forums/e-class-w...d-timeout.html

I was also doing test run on the new LEFT FRONT tire and wheel, as per this thread : https://mbworld.org/forums/e-class-w...d-highway.html

I did the OBD2 data insertion into the video was to see my less than optimal turbo boost due to small minor leaky check-valves at the intake manifold discussed on this thread : https://mbworld.org/forums/e-class-w...re-sensor.html



With the video showing the instrument cluster : transmission mode and the gears changing can be studied and it helps alot.
I have summarized the very first time the occurrence started and many occurences later during that test run, till I head home and troubleshoot the problem.

Yep, lots of Beep-Beep censored swearing... ha ha ha




My last scan 2 drive cycles ago using Xentry on the car did showed DTC but a stored one, so I thought it was simply a glitch. Stored is historical and not current.
Xentry showed : P277900 Steering wheel shift button 'MINUS' (-) has a mailfunction. So this means the left one, the downshift. The reporting unit is the N80 Steering column module (SCM)
Xentry also showed : U042900 Implausible data were received from the steering column module. The reporting unit is the Y3/8N4 - Full Integrated transmission control (VGS)


So after the troubled test drive I scanned the car again. Ignore the N3/10 ECM DTC, that is the alternator LIN removed.



So, the same two DTCs I mentioned earlier did come back, as per above.


Here I also realized things I did not know about Xentry ( pass-thru version ).
When I do general or SCAN-ALL, the read out data is actually not the same as if I go into the said module directly.

Example below : This is from SCAN-ALL or Xentry called it Quick Test for all modules.

See above : First occurrence and Last occurence is the same 35,168KM and status of DTC is STORED.

See below, if I go into N80 module directly and read the troublecode and expand it. First occurrence at 35,168KM and Last occurence at 35,184KM and status is CURRENT and STORED


damn.... why MB is so information stingy during a Quick Test ( SCAN-ALL ) ..... LOL


Below is the cause and effect of P277900 Steering wheel shift button 'MINUS' (-) has a mailfunction at N80 impacting Y3/8n4 and hence the U042900 Implausible data were received from the steering column module. pops out







Again, going into the module directly has better information. The Last Occurrence data is there , the accurate one. CURRENT is showed along with STORED.



Looking at the wiring diaghram for the DOWSHIFT switch





I am attaching the wiring for N80, for those who may want to learn more. The schematic only pdf is a nice landscape view no cuts of the wiring pages.

When I saw a 2 wires only switch for the UP/DOWN shift paddle and module can report its status as MAILFUNCTION, initially I thought are they using N/C ( normally closed ) switch and not the common
N/O ( normally open ) switch and schematic indeed showed a N/O switch type...except for UPSHIFT one with a diode.

So I must test myself, is this an N/O or N/C type switch ?
It is an N/O switch with minor ohmic resistant pad as its contact point. Its like a keyboad switch. It is a Momentary Switch.
So the definition of N80 module able to report a MAILFUNCTION , it can only means SHORT-CIRCUIT or always closed position.
N80 can not detect physically a missing switch or always open one. I tested as such, N80 can not sense missing switch.











My only mistake is, I did not measure the resistance of the switch un-assembled internally.
The switch is fine. I am wondering if the black resistance contact point got chipped off a bit and fell to the circuit board copper trace and created a DOWSHIFT trigger ?


ABOVE : See some black contamination at 3 o'clock of the yellow silicone spring/cup ? Its total length can jump the small gap of the copper trace at PCB.


My transmission in any mode be it E or S , once I demand a gear change ( usually downshift ) using the pedal shifter, tranny will allow and will be in M mode for like 10-15ish seconds or so
until no more manual override activities happening and it will then go back to E or S mode.

My theory is :
If the contamination created a rather long or permanent contact or DOWNSHIFT status for certain long seconds, N80 module may declare a MAILFUNCTION or a short circuit.
I can test this next time with downshift switch taped down permanently to simulate a short circuit or contact-always and drive around and see what N80 will report as DTC.

If the contamination jumps around touching the contact trace at PCB, it will create a DOWNSHIFT demand.

After the repair I did a short fuel buying run, short run under 5KM and no issue.


Will continue later on what TO DO AND NOT TO DO when removing steering wheel AMG type (face-lift 2014 up W212 ) like mine. Its not as friendly as the older model.

S-Prihadi

Let's discuss the N80 Steering Column Module (SCM) strategy first.
After the test drive with the tranny issue, first thing to do was to scan it and get the DTCs, usual move.

What I am keen to learn is, how N80 manages the car's transmission to be still operational despite having issue with the S110/1 DOWNSHIFT Pedal switch ?
It seems the N80 kill the connection to S110/1 , just like a short circuit wire to a headlight or other exterior lights.

With DTC P277900 Steering wheel shift button 'MINUS' (-) has a mailfunction still CURRENT or ongoing, Test function menu showed no reaction or reading by N80 when I pressed the DOWNSHIFT switch.
So N80 killed that particular data channel to S110/1 Downshift.



At the same time the N80 seems to inform Y3/8N4 - Full Integrated transmission control (VGS) to ignore BOTH DOWNSHIFT and UPSHIFT buttons actuation.
Do remember, status wise Ys8N4 is still flagging/CURRENT DTC U042900 Implausible data were received from the steering column module
How I come to such a conclusion ? Because when I use Y3/8N4 test function below, to detect downshift & upshift switch actuation, BOTH switches does not work for Y3/8N4 but UPSHIFT works for N80

So its like a safety blanket performed by N3/8N4, if one switch down, both is then to be ignored. Make sense though as these two switches are husband and wife duo


When the DOWSHIFT switched cleaned up and re-installed, the Test function both at N80 and Y3/8N4 - Full Integrated transmission control (VGS) can read my manual actuation of the switches.











Now for techical-junkies like myself and Senor Cali
The so called N135 is explained and shown below :


N135 is small electronic board which is an interface unit for all switches on the steering wheel only ( not at steering column N80 ). From B135 all switches actuation is reported to N80 via LIN, so only 3 wires needed.
N135 to N80 using LIN data. N80 to other modules uses CAN BUS.
This is odd, Xentry usually shows LIN connection...not all but decent, examples headlights and other LIN based devices/modules, in N135 case...you need to see the wiring diag of N80 to realize that there is a LIN and
a small baby branch circuit called N135. NOTE : Xenty has a Network Topology function......... that is even worse, many LIN devices are not listed/sensed.





There is a test function to see if N135 is okey. But if many steering switches went banana, it is surely N135 issue.



I missed the chance to improve by soldering this N135. It is so small I thought the pins are soldered type and not the insert type, that is untill I zoomed the photo in PC and steering wheel already installed.







WILL CONTINUE.................

CaliBenzDriver

Thank you Surya for this awesome investigation down to the tiny contaminants: bingo solved like a boss!


MB really has no place to hide issues away from you. Who could tell the downshift contact could be morphed into a cheap wear item for turbo driving?

Laggy SCM response:
I find the steering wheel buttons fairly unresponsive at times when I open the voltage menu. I don't know much about this important module except its not a real champion.
Perhaps your shifting experience is similar: "press and pray"... "please shift as-soon-as possible"!
👏

I am super interested about your tips to remove these steering wheel.
My next dismantling is going to be steering column. You know me... going to resolder SCM, EIS, ESL modules. I've seen the IGN circuit uses pressed-pins...

The steering "clock spring" is a delicate item that should be kept indexed with paint markings, right?

S-Prihadi

HOW TO REMOVE THE STEERING WHEEL...actually only removing the airbag and parts of the steering internal


My version the unfriendly-to-remove , the POKE-BLINDLY-VERSION...for me it is unfriendly until we actually see clearly the locking mechanism of the airbag mini b0mb.

Someone's else car.... but that is my steering type.


DISCONNECT BATTERY NEGATIVE WIRE FIRST !!!
Allow capacitor discharge in modules, open door and ignition key in position 2 ready to crank , keep it there for 30 seconds will do.

Video is better for visual.


The airbag will automatically pop out due to its springs, so no need to pry out the airbag module.

AIRBAG LOCKED IN LOCK PLATE SIMULATION













To remove front shiny faceplate ( where switches are )........
2 of T20 screws behind the steering bottom middle ( 6 o'clock ) and 1 of T20 screw at 9 clock and 1 moreT20 screw at 3 o'clock inside the steering and visible when airbag removed, near the LEFT / RIGHT
switches assy.



Now I realized why the old fashion way of pushing the steering's middle part for HORN activation does not work well in my W212 .... ha ha ha.
Must do 3 or 9 o clock top part or very low 6 o'clock push for HORN, so me no need to fight 3 springs of the airbag locking plate.

S-Prihadi

AMG style steering wheel removal, real removal



Older style

S-Prihadi

I rarely use my pedal shift, I just kicked down a lot hehehehe.

The steering "clock spring" is a delicate item that should be kept indexed with paint markings, right?
If you mean steering rack shaft to steering wheel, just mark it should be good. I am sure you want to go all the way and remove N80......... yipeee !!
The two youtube videos I linked at previous post, the 2nd one showed N80 removal.

I did not remove my steering wheel yet ...just undress it a bit

I think all the 12 ish total switches best to be cleaned at its contact point if long term.
At the same time inspect the springy-ness of the silicone membrane, assumed all are like the DOWNSHIFT silicone + contact pad. Torn silicone can happen.
Dust settling at the copper trace at switch PCB can also happen.
These are like soft-switch, almost no load current, its a signaling switch only.

CaliBenzDriver

Another great textbook-perfect investigation.


It looks like our carbon rubber button could use a lubricant film to prevent surface oxidation.
I just don't have much positive experience with this carbon deposit over silicone.
The last thing we want is to help the carbon chunck off more loose pieces or create an abrasive sludge.


You have just writen my next assignment 👍
Go fix pins around the steering head + now with a new bonus LIN module for our steering buttons.


> Sounds insignificant... not really: mojo!
When I reworked the LCP button module below the Comand head unit, I saw how those LED glow brighter. These modules ate loaded with worthy electronics that consume power (~1000mA peak)

Same thing is true about in-mirror blind-spot LED: brighter... tells me it had some voltage drop, glitching the signaling from power supply of 3-wires LIN --> Bandwidth for "Error Correction" retransmit is a big deal on slow LIN buses or busy CAN buses.

Note this as my famous-secret:
​​​​"EC > bottleneck > latencies > errors > failures!"
NOISE REMAINS MB'S ENEMY #1


It is difficult to hunt for improvement without hand-on! Only total noise removal is satisfactory... ALT- LIN
​​​​​​

Again thank you very kindly Surya!
I realize without your science, we wouldn't have progressed to be where we are with these cars.

Senecat

So do you like, just work on your car all day every day or what Lol

Thanks for the great info!

S-Prihadi

well yes.
The car is more like a Gym, Lab and fun-machine combo, transport being last as I have other cars.
I can't generate sweat on treadmill or static bike or my pool, no fun. I rather sweat doing tire change or under the car doing something.
The electrical and electronics is the Lab part, it keeps me wanting to learn more of today's technology....I am weak with IT.
The fun-machine is when I can abuse it at the track for fun, drive long distance enjoying the road and scenery and seeking components near its
creme de la creme expiry limit and replacing them.

Car breaking down unexpectedly is an insult to proper preventive maintenance. I am trying to avoid it.
However this E400 is so loaded with electronics, any electronic based failure is unpredictable...but in the long run maybe 10 up 15-20 years, the capacitors in them will leak/fail/shorted for sure.

CaliBenzDriver

> Help with w212 capacitors:

I have not seen many evidence of premature caps defects except for the capacitive AUX replacement and audio Amp.

Build quality is functional, margins are cut thin all around: power is being filtered with 47uF instead of 220uF.


47uF filter cap 🤪 (soldered + insulated)

10% oversized caps, could save the day by doing their job to smooth more riple noise. Overall MB is after squeezing the envelope to create glitching opportunities.
Just how fast the electronic smokes or the software trigger a fatal exception is managed by objectives ("MBO").

The one toasty module where bad caps can be forcasted is the ECU. It was moved from the engine crown horizontally to vertically over the exhaust collector... cool ✌️

The thermal paste used inside the 2x audio amplifier modules reportedly desintegratres into liquid gup forced down by Gravity, specially in verticall main Amp, less so in smaller horizontal sub-woofer amp.

> Steering wheel buttons:
I have reworked the button tiny control board but can separate the steering facia to access the circuit boards behind buttons LIN.


can't separate the 3rd spoke... is it glued or what???

S-Prihadi

============ as quoted earlier at post #4 =================
To remove front shiny faceplate ( where switches are )........
2 of T20 screws behind the steering bottom middle ( 6 o'clock ) and 1 of T20 screw at 9 clock and 1 moreT20 screw at 3 o'clock inside the steering and visible when airbag removed, near the LEFT / RIGHT
switches assy.
================================================== =


You are most welcome


Quite many W212 MB's ECU failed in my country from the capacitors failure, mainly leaking.

ASK : Do you have heater and the steering shaker ( lane keeping assist ). I am wondering how the shaker/vibrator looks like and its size and where is that located.
Steering wheel is a big size object, I am curious on the shaker design.






If you have steering heater, the left side connector from N80 will have 5 pins and not 3 like mine a no-heater car.





I don't know if these are lights effect from flash photpgraphy or oxidation of the copper pins at the N80's connectors (2) to steering wheel.
I have to tear open the steering one more time when I am done testing the tranny for at least 1 more drive cycle of 25+ KM. Soldering those push-type pin is worthwhile.

Left connector, the one to N135 switch interface board.
Looks kinda dark, like dirty-ish yes ? I will need to see upclose with my 20x magnifier later on.




Right side, airbag one. Dang is that dark stain grease ?




I should have worked on the steering using my book reading glass (20-30cm focus target ), daily I rather use my PC glass ( 80cm focus target ).
I dont like wearing do-all progressive glass, I get headache . I drive with driving glass 3 meters and above focus distance.

CaliBenzDriver

thank you for saving my bacon with the 2x T20 facia screws at 6 o'clock ... must be a señor moment !



So now I got more stuff for ya...

> Shaker please:
This little feature is one that I quickly disabled around 10kMi. I recall the shaker works with both "Attention Assist" & "Lane Keeping Assist".

The wheel shaker itself is not bad, it's the grabbing electric steering rack and slamming the brakes in a diagonal pattern, I hate with pation! This all happen because of confusing road markings or drving around town over markings.

These two primitive features are useless, unlike the Distro+ that drives your steering, brakes and gas perfectly well on Hwy.


stick-shaker @ 6 o'clock
This familiar feature is for jumbo jet pilots while on leasure drives: cockpit voice missing the "pull-up, pull-up!" warnings.


simple 2-wire rotary shaker

I did not order the heated steering package. The circuit board has unpopulated position so it may be a specfic match module+Heater.
Another not easy PlugNPlay upgrade, need a whole new wheel.

> Wheel connectors:
My connectors look decent so far, no heavy discoloration. I bet you are dealing with many cycles of A/C condensation in trolical Jakarta.

While driving, everything metallic inside the car drops temperature near your cool A/C temp. When you stop, the cool metal condensates the H2.O humidity out of the air ever so slightly time after time. You know all that well, right?
It's the exact same principle that makes the pressed-pins components become trouble makers given a chance.
The sected metal oxide is conductor but less so than a clean surface-surface. Resistance develops, gets gradually worse.
I am sure the genius engineers studied that oxidation slope to adjust the metal alloy for desired oxidation rate.

Evidence of carefully managed quality:

SRS: copper/brass vs. Buttons: nickel/tin!
Germans are the uncontested leaders in the field of metal alloys... they're not idiots but neither are we .

This is a call for an anti-oxide contact protection that may not evaporate like a petroleum oil does. I am sure there is a great industrial solution to this age-old problem.


air bag side connector: mostly shinny.


button side connector: little discoloration

> Un-comanded safety up-Shifts:
Speaking of odd shifts issues, I was reading a thread about low-engine oil or failed oil sensor that make the TCU up-shift to keep engine RPM artificially low. Good general knowledge to remember in the tranny oddities Dpt.

Now let's look at steering buttons before pulling the wheel off down to the SCM level... confirmed pressed pins in use on module + side buttons ✅


Str buttons daughter boards: pins
In total just the steering wheel module has 3 boards with pins.


downshift button
Minimal contamination is found with couple tiny loose specs. Still small for now.


need to upgrade my cheating skills
Dealer must have impacted my wheel back on when they performed the convenience entry TSB on my clunky steering column. Zero improvement, so I've disabled that too

Impact socket to the rescue!
...wheel's popped > onto SCM + EIS modules

S-Prihadi

Wow...your airbag connector ( right side connector ) at N80 is so clean .
Your multibutton (left connector ) is also much better than mine.
Its very much so my city/country humidty is the killer, for the last 2 years, being in Bali 800 meters from the sea for 1+ month each visit is also not a good air to have for electric stuff.

I been studying the connector types & quality for the male and female pins/terminals for the engine side sensors.
I am still waiting for many special ordered ones from Germany.
Learn a lot when doing the order and research for their brands and models. When all arrived, I will so a special thread on them.

Our pins/terminals I am sure are the silver plated one, or minimum being a tin plated one.
Basically I am not to see any copper-ish color on my connector pins/terminals if they are still properly maintaining their plating.

This is the silver plated ones : Mercedes uses a lot of MLK1.2 type
FEMALE https://www.automotive-connectors.co...se-pieces.html
MALE https://www.automotive-connectors.co...se-pieces.html

TIN plated MALE : https://www.automotive-connectors.co...se-pieces.html


I see, that is where the SHAKER is, thanks Cali.

CaliBenzDriver

You're saying our car uses silver plated connectors for general harness and copper/bras alloy for SRS ?

I wonder what anti-oxydation chemistry have you found would best match these metals alloys?

Some people use that on their ECU connectors to keep things on their best behavior.

S-Prihadi

Mercedes uses 2 main connector brands, I am speaking of my W212.
MB use other brands too but the two below is by far MB top choice.

1 is Hirschmann https://www.hirschmann-automotive.com/en/
Many are the SealStar 1.2 family FEMALE https://www.hirschmann-automotive.co...star-12-female , MALE https://www.hirschmann-automotive.co...alstar-12-male
However, the pins and terminals are using MLK or MCON standard.
So Hirschmann make the plastic body, female and male, but not the male pins and female terminals.

1 other is Kostal https://www.kostal-kontakt-systeme.c...s/produktwelt/
MLK male pins and female terminals I believe belongs to Kostal. https://www.tti.com/content/ttiinc/e...terminals.html
MCON male pins and female terminals I believe belong now to TE Connectivity. https://www.te.com/usa-en/product-2177610-1.html

1.2 aside from Kostal MLK family, it is also dimension of the width of the male pin of 1.2 millimeters.

So connector housing manufacturer appoints say 1.2 MLK male pin and female terminal, this means the dimension for where the locking tab is, waterproof seal and yada yada is all set
to work properly for 1.2 MLK.

I am still learning and it is confusing.

MB buy a lot from Hirschmann & Kostal, as such many model are not sold openly in the market because it is MB Specific... S.O.B.
The male pins and female terminals are easier to buy in open market.

However, we need to be careful of the exact type. Example below : 1.2 family. https://www.ttieurope.com/content/da...N-C0111902.pdf



MLK ELA type has a small hole at its cable end to allow waterproof seal to be crimped, see below



Its damn plenty to read to understand all these male/female pins/terminals. There is so much science in it.

https://www.automotive-connectors.com/wiki/

Silver coatings are used

• with high-current contacts,
• with a mating frequency of 20 to 50,
• if friction oxidation is to be prevented,
• if the maximum operating temperature is between 140°C – 160°C.

Tin coatings are most commonly used when:

• the insertion frequency is between 10 and 20
• and the maximum operating temperature does not exceed 130°C – 150°C [1].

I been shopping around the world for connectors and male/female pins/terminals.
UK, Finland, Germany and MB Indonesia.

The idea is to avoid back probing connectors if possible and make a custom and dedicated troubleshooting wire set.


Example, camshaft position sensor A0225452426 is a Hierschmann SealStart 1.2 3 pole/way, keying code A.



I managed to get the female and male connector for above, from open market.



So I made a non-intervention test wire set. I call non-intervention because the connection between male and female connector is fixed, permanent, all I can do is sense the signal voltage but can not read amperage using DMM.

Later I will make an INTERVENTION test wire set for above. I got 3 set male and female connector body for above.


Below the yellow and black 4mm banana connector stacking type is an INTERVENTION type test wire set, but without connector housing of dedicated sensor/s. I can read small amperage using DMM this way.
Their male pin and female terminals are the 1.2 MLK family




I bought this and unhappy with the type of the male pin and female terminals used, they are not suitable for german cars or MB. Suitable for US cars.
https://www.aeswave.com/54-Piece-Aut...Kit-p9606.html

Also the AESWAVE test wire set has a bulge for finger grip, it is blocking entry to sensor connector.



For a Hirshmann 1.2 SealStar female connector ( sensor/device side ), it is very slim and I must not have any bulge on my female terminal test wire.



Also a standard female terminal is not long enough to push in accurately into sensor/device male pin , so I first soldered a 1.5mm solid copper wire as a "stiff" extension of about 8mm long for the female terminal.



Quite fun actually all these.

.

Senecat

I smoke way too much weed to follow you on most of this stuff Prihadi but I appreciate the compendium of info you provide to us nonetheless!

S-Prihadi

After the "repair/cleaning" of the DOWNSHIFT pedal switch and I drove a bit for fuel and then no DTC when scanned........ few days later ( car was not used at all ) I scan again and funny a stored/historical DOWNSHIFT pedal switch mailfunction pops out again. I did not screen capture it though, because the registered mileage of the DTC was within the trip to buy fuel... funny.
I call above condition as DTC Glitch. I have seen such odd cases on N62 Parking System ( PARK ) module too, also STORED.


Anyhow, for the 2nd time I inspected and cleaned the DOWN and now UP shift switches and at the same time take a closer look at the connector B1 and B2.

B1. Left side, for all switches. It seems the silver or tin coating is rather worned out. I see a tiny copper-ish color and not the very shiny silver/tin. I wonder why.

For B1 connector, I applied De-oxit , after I took photo of it.



This must be on purpose by MB Indonesia. Grease at B2 connector ( right side), airbag connector . I dare not clean it, because so far so good and air bag system reads very low 2 ohms-ish resistance when all bags OK.



Connector B1 and B2 male pin ( steering side ), easy view of pins assignment






Just sharing............
Autel MS806BT can identify the manufacturer of N135 switch interface board as Marquard and complete information on it.






.



Xentry Pass-thru does not have similar information.. WHY ???????




Xentry pass thru has test feature to test N135 board, I don't know if a 100% or just the heater & vibrator motor. Autel does not. Below screen capture is 6th March, first time I cleaned the DOWNshift button.





I tried soldering the push-pins of N135 board, but I was NOT in the best of mood. Only did 5 spots and I stopped. 2 + 2 spots for the DOWN and UP shift buttons and 1 more spot is the common ground of the horn.
I use a new 20 watt sharp tip soldering, not easy to use for such long male pin radiating the heat fast. My other temperature regulated soldering iron is better, but its tip too fat.
Overall I sucked at soldering something his small....

The connector B1 and B2 is made by Kostal. Its male terminal and male pins are MLK 1.2 type. Attached the B1 connector spec sheet.


Fault Code List possible from the N80, the boss of N135.





.

CaliBenzDriver

Surya, you know your crazy self shifting buttons could very well be created by the multi-stack pressed-pins modules and the not so good looking steering connectors at steering wheel right?
At least fix the wheel controller board with brown connector down to clock-spring.level.


Once you had me pop the driver air-bag unit, I did not stop... I took everything a part all the way to the steering knuckle at the bottom.

This thing needed a fair bit attention with 3 different layers of pressed-pins (button board, wheel module, steering angle module, SCM) plus the clunky easy-entry assembly with the dry bearings and the dry control switches. Great modular assembly with a few troubled details.


Now something else has my attention... My silly OCP has me scratching my head. The buttons are working, the OCP module is communicating normally with scanner except ALL VALUES of the Live Data are N/A (Not Available)

I wonder how that is even possible. Is this a case of half missing CAN signal or a corrupted firmware.

BTW, no fault code! Maybe that's all I need... to trigger any code that would enable scanner CLEAR for a formal reset!

S-Prihadi

Soon I will solder those pins of N135 Cali. Perhaps also the left and right multi buttons.
N80 probably I will leave it alone.

Did you open up N80 and solder them push pin (if any ) ?
If you did open up, photos of how it looks like inside and the board...please ... thanks

CaliBenzDriver

Yes, take care of your 3x steering wheel circuit boards, at least. (perhaps use scuba "O-ring" silicone lube over carbon surfaces).
You don't need to pop the wheel off, only airbag unit so It's quick and easy fun.

Remember, we were talking about lubing silicone button carbon surfaces... I just got done doing that to driver door master window module... for better or for worse, we'll see.
I have not powered up yet for testing, that is what's next! I'll publish things later, ok?


my trusted silicone goodness

>Afternoon EDIT#1:
- As far as I know now... Scuba gear silicone grease is perfect for soft carbon switches (lubes friction and protects oxidation) as tested on driver seat + windows sw + OCP. I will redo steering wheel buttons to add silicone

- Need to probe lazy OCP module for Pwr circuit 15R with DVM & schematic.

- It's not always easy to predict things upfront because of car complexities. I can tell my CAN-B response time is ridiculously faster (Cluster, Comand, Display, Seats, Mirrors, Trunk, Locks, EIS,...).
Debugging this slow-poke networking CAN vehicles is starting to amaze me.
✌️

> EDITS#2:
I've just earned a "PRE- SAFE Limited..." IC display message while driving!!

It is the MFK module erroring about a collection of mBrace errors that are caused by my missing/unavailable OCP buttons.

So it's my crazy OCP jacking up PRE-SAFE... it's not a fancy failure, just the busy OCP module.

OCP does A LOT of stuff! (sunroof, mBrace, Lights, AAC Temp sensor, MFK module, Rearview mirror)

I still need to resolve my "OCP blank data"... who knows something??