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@S-Prihadi Once again, thank you very much for all the useful information.
Quick answers:
- I will check the connections at the trunk. I did the grounds back then with your GRND campaign, took the RearSAM out, opened and soldered it with @CaliBenzDriver guidance.
- I will check the F32 Prefuse box and the voltage drop suggestions
- Still have the GRND point clean-up pending, CAN blocks check, and the house chores list to complete,
Keep you posted. So far, the car has not done it again, fingers crossed.
Still need the answers Two important questions ; 01. Is your car a B03 Start Stop with 12 Ah battery at the trunk ? 02. If your car is B03 option, was the Start Stop active when all these troubles happen ?
=================
Do you have any means to check pin fitment for the connector's terminals ?
You will need the male terminal as the verification tool, as the problem one will almost always be the female terminal.
Your problem seems intermittent, and this is the Queen Bi-tch of a problem we all hate.
Intermittent power loss or massive voltage drop can have the same result as CAN BUS LOST-COM or, the CAN BUS itself has intermittent bad contact. Its all in the integrity of the connection/terminals.
I had pin fitment issue during troubleshooting my friend's M271 EVO engine, it so happened the female terminal for Ignition Coil one was not biting well the male terminal and causing mild misfire.
I was lucky that the trouble occurs more often than not, so easier to track. The load was 10 amps.
Because of this M271 experience and my desire to make custom test connectors using OE connector, I then started collecting as much as I can MB's female and male terminals and MB connectors,
which the terminals in use are mainly the MLK 1.2mm and SLK 2.8mm and smaller ones for CAN BUS terminals like 0.65mm ones.
My friend's M271 engine also pissed me off because at that time I only had the under-powered and shared grounding 2 channel picoscope and can't read more than 2 signals at a time or single channel only
when the needs dictated that I can't use shared grounding type scope.
Above is a very good case study of intermittent bad contact of super short duration.
ABOVE: Basically what happened was : at the right time, the bad fitment of the baby female terminal have gone the extend of an open circuit which equals to a lost of ground for 0.2 seconds ( hence shot up to 5 volts )
and caused HP fuel pressure sensor to read wrong fuel pressure and ECM acted wrong in response and misfire occurred.
Imagine the above scenario is happening to either +12V or -12V supply or CAN BUS High-Low in our car module.
Below is a CAN BUS message, 1 message at 0.23 seconds long. Imagine we loose 0.2 seconds which is 1 message lost or could be two messages : a tail and a head, depending on where the loss occurred.
Without a scope and his patience, the Mr Carter the techy most likely will never find the true culprit unless using intrusive method.
Connectors to ECM with so many pins (40 to 90 ish terminals ) are not easy to shake-shake and get bad connection to worsen on demand.
This kind of issue is where some lazy techy would simply said, GET NEW WIRING HARNESS
Have fun............
ADD======
During the M271 EVO toubleshooting, I do not yet own any male terminals for MB, to do fitment test.
So I use this type of welding tip cleaner as fitment tester :
@S-Prihadi , some answer to your question
1 - w212 with ECO, and the motorsporst battery size, not the tiny alarm type. @12Ah
2 - I occasionally turn ECO off, particularly in traffic areas, it does not matter on the highway. For those instances, I do not recall, but I will keep it in mind as I monitor it.
3 - so far good. It has not come back, yet.
4- very aware of the pin connection quality, and I am very careful around ECU connectors since reading your M271 nightmare back then
5 - looking for inexpensive scope, it those even exists. Not only for my cars, but to diagnose an intermittent shut off of a friend's 928. There were no computers Back then, and learning. Last time I used an oscilloscope was in college lab @1981.
Still planning with GRND campaign, and pondering SCM preventative maintenance.
Aside from memory/sampling bandwith, not frequency bandwith, a floating ground scope and a common ground scope is a big difference.
If you already have a laptop, best bang for the buck would be the Pico non automotive 2204A 2 channel 10 Mhz. Common ground. This unit wont allow you to use Pico's automotive software (free), buts its OK.
Pico non automotive software ( free ) is also very good.
The software is very important, this is where Pico shines.
Laptop based scope is cheaper due to no display. So the $$ can go all into its internal hardware.
https://www.picotech.com/oscilloscop...-2000-overview
My 1st buy is the Pico 2205A 25mhz 2 channel, after M271 EVO experience I went for the 4 channel automotive floating ground 4425A, 20 mhz but 12 bits vertical resolution vs 8 bits of 2204a.
Danger of using non-automotive scope with common ground, aside from the fact you need attenuator ( cheap ) to allow a 2204a test higher than 20V ( 4425a is 200V ) or prevent induction spike of a 12V system like relay and starter coil
which can shoot up to 100+ volt killing the scope, is one must understand the wiring and function of the device under test.
On a bench test type industrial scope, the same common EARTHING/GROUNDING between its 2 , 3 and 4 channels is an issue too when operator is not careful. Using a differential probe can avoid it but it cost a lot.
Since my laptop for my car is only 1 unit. It has Xentry and Picoscope software.
At times this is not ideal running both software at the same time. Xentry uses USB to laptop and so is Picoscope. Those USB has grounds too.
If I need to avoid issue with grounds, I then use Autel to replace Xentry and let laptop run Picoscope software only and sometimes I do not use the laptop power supply and purely battery powered, because the car battery maintainer is using
also a power supply from the same main 220V. This is more for noise control strategy when I need to let laptop uses its own battery.
Do you know why I was so interested on these two questions : 02. If your car is B03 option, was the Start Stop active when all these troubles happen ?
A long time ago, before I killed the ECO-START-STOP , I was always wondering, what failure mode can happen to this V19 Q-Diode ?....which is part of the ECO-S-S required component .
If the Q-Diode simply dies in OPEN state, it is easy to troubleshoot.
If the Q-diode dies in CLOSED state, one probably will never know about it as it is okey, power can flow from battery to F32 to all parts of the car, no issue.
The Q-Diode is like a relay, but solid state and very low voltage loss....so it claimed.
This is an accurate but simplified hard wiring of F32 overall ECO-S-S system. Only Circuit 30 ( always HOT/ON ) shown. I do not show the Circuit 30g from K2 relay.
ECO-S-S only deals with Circuit 30.
Below was one of the test I done in May 2021, trying to understand ECO-S-S
Above : See the Instrument Cluster showing 13.0 volts and Zero amperage. Do you know what this means ?
This is the time Q-Diode actually OPEN, or disconnected itself from F32. This means the entire power needs of the car now is from alternator G2 and the 12Ah baby ECO battery at the trunk.
This also means relay K114 of ECO bat is CLOSED/engaged and ECO bat can join the Circuit 30 of F32.
Instrument Cluster voltage and amperage data is ready by B95 battery sensor at the main battery negative post.
The showing of 13 volts is because before Q-Diode OPEN or disconnected, it was connected and alternator was charging the main 80Ah battery . So 13 volts is the surface voltage of the main battery and Zero amps shows that Q-Diode is OPEN.
Note the time stamp of the video is 03:37.751 minutes.
The alternator at this point in time is pumping out 13.9 volts and the entire car power consumption of 35.2 amps or 36.8 amps minus 1.6amps the 12Ah baby ECO battery is getting. Again, here relay K114 for ECO bat is CLOSED/engaged.
If Q-Diode is CLOSED or engaged , it will show main battery getting positive charging amps ( assume alternator is 13V and above ), like below a 2nd video screen capture at time stamp 3:26:339 minutes or 11 seconds
prior to 1st video screen capture where time stamp was 03:37.751 minutes.
Above amperage state is : 67.1 amps gross output of alternator , 33.2 amps goes into charging of main battery and 1.6amps went to charging of 12Ah baby ECO battery, hence car power consumption was : 32.3 amps.
So above means Q-Diode is CLOSED/engaged and so is K114 relay for ECO 12Ah battery.
Below : An early minutes of the same video will show you where 12Ah ECO battery is not yet being charged aka its K114 is still OPEN or disconnected, but Q-diode was CLOSED/engaged and charged main battery. Time stamp 3:15.829 minutes.
Now, the WHAT IF........... what if Q-diode is slow to response but not dead in OPEN/disconnected stage ?
The scenario as follows .......
For some reason K114 relay is engaged but Q-Diode is OPEN/disconnected, so car has a battery as buffer, but a small 12Ah one. All seems good because alternator is okey and can provide power.
A driver wont know this happen, unless he sees his Instrument Cluster showing zero amperage and whatever the main battery voltage was at that point in time.
In a cold climate, where radiator fan wont need to run fast, the biggest power sucker for the car and also a sudden type of power sucker is : the electric power steering when doing U turn or any big angle changes of steering wheel. This is a 50-60 amps sucker.
Now, assume the alternator is doing its famous voltage YoYo at the same time with above unfortunate condition, a low voltage yoyo...... a sudden but short and a very low voltage can then occur. I think a mere 0.5 seconds of super low voltage <10.6V can be a problem.
I read somewhere ( Star Tuned Magazine ) if system voltage down to 10.6V , this can create all sorts of modules error.
A 60+ amps load to the baby 12Ah ECO battery can probably create a <10.6V easy.
Do note : once alternator voltage does not go above 12.6V, baby ECO battery is then the sole provider for car DC 12V power. Also alternator is not the fastest type of power demand responder, battery is.
Do remember, when and if Q-Diode is OPEN/disconnected, the car has 2 separate and isolated voltage system
One being main 80Ah battery voltage (dormant) as read by B95 battery sensor and the other voltage is system voltage from alternator and 12Ah ECO battery and read probably by the engine's computer if not Front SAM.
Since we have seen Q-Diode is capable to OPEN/disconnect itself from F32, the above scenario is always a possibility when Uncle Murphy decides to be naughty.
I killed my ECO-S-S because I hate the jerky-ness it caused from an engine stop/sleep to a hurried accelerator pedal pressing at traffic light or any short duration stop at a junction when I wanted to turn right after waiting for opposite traffic to clear.
I also do not like to depend on more devices which will someday fail, like Q-Diode, K114 ECO relay and the 12Ah ECO battery.
The Q-diode is what I fear most because its is solid state and therefore unpredictable and I do not know how its "bad" contact behavior will be for such mosfet/transistor or whatever it actually is.
Showing how EPS is a true power sucker and how alternator is not a fast enough power demand provider compared to a battery.
Above, so far so good.
Below : See how fast a battery response to pumping out 36.6amps and have its own voltage drop to 12.9V while still having a parallel connection to an alternator system pumping out 13.5 volts and 78.6amps.
This is fast sudden local voltage drop of 0.6 volts at battery. I seen this often where 2 power sources are involved/parallel and sudden big load comes.
Imagine if the alternator is at ECO mode doing 12.0 to 12.3V and the battery in the above scenario is instead the baby 12Ah ECO as the sole provider of 115 amps ?
I was wondering what you were dealing with this "Quasi-Diode". Welcome to the world of power semiconductors.
The manufacturer using the name diode is misleading ... This switch primary function is accomplished by a TRANSISTOR, itself protected by a conventional "diode".
It's actually the solidate state relay used to update the Big-O' electro-mechanical SPST relay that disconnect batteries out from car circuits.
Function is nearly identical. It's a controlled "ON/OFF" -Or an "OFF/ON" SWITCH that includes a built-in diode. Meaning in reverse switch always acts as closed though the diode path, with 0.6VDC fixed voltage drop in reverse.
Protected Power MOSFET
The standard built-in protection diode between Source > Drain is used to protect the SSR from reverse voltage spikes the MOSFET can not handle by itself.
Automotive switch application
These are characterized by low RDS-ON drop voltage and high current with zero wear factor.
These SSR work perfectly until exposed to voltage spikes or reverse bias voltage beyond protection.
This is the sort of longlife switch you want on street traffic lights or refridgerator that cycles On/Off 24/7 all its life.
As far as Benz dual battery connected/disconnected by Solid-State relays: AUX is used to power the car while MAIN is disconnected from circuits to only cranks the engine.
This prevents low voltage and fluctuating lights during crank.
The disadvantage from these MOSFETs SSR is they always leak through a little bit of current even when blocked Off.
90Amp batt charge/discharge 11V Yoyo:
in cars subject to extreme alternator outputs, these SSR relays visibility get toasty hot as witnessed by discoloration.
check GND !!
The last thing we want are these relays acting crazy from painted GND on the control side. These switch battery load +/-50Amp. Check power connections are not overheated from the 90A on yoyo days.
> QD-Relay... Yoyo duty :
- The main Batt is connected through "QD-Relay" to the rest of the car to prefuse circuits.
- Starter is connected directly to batt post.
- The only current through QD-Relay is charge current (+10Amp) and car circuits (-35Amp) when engine's stopped.
- There should never be 90Amp coming through this relay drained by the alternator near 11.xV. This path is not sized for that load duty.... > Inspect Prefuse box !
When MAIN batt is low, AUX is going to chip in through diode or SSR. That's how AUX batt gets wasted by the Yoyo chaos. ✌️
I am starting to think of the relationship between 12.0V and 12.6V... how this may in fact be the SSR diode when QD-Relay is opened... check control side!
Yoyo Scenario:
ALT puts out 12.6V float voltage but SSR diode drops 0.6V equal 12.0V read by battery sensor, right?
--->> Make 100% sure QD-Relay GND is good. This controls power to VIP's and all.
> Related or not:
QD-Relay may be a factor in YoYo discharge but I don't think it is linked with either the "soft-crashed Direct Select" or the "No Crank from ISM".
I used to have 1st class Yoyo but I've never faced the stubborn gear selector.
> Check QDR GND:
Where do both QD-Relay get control side GND?
+ W2: Footwell ?
+ W7/8: Trunk side "wheel housing" ?
QD-Relays control GND paths !
We know semi-conductors are extremely fast. These QD-Relay can switch in the KHz speeds, creating sweet chaos from marginal 5¢ GND screws!
Last edited by CaliBenzDriver; 01-29-2023 at 09:23 PM.
@S-Prihadi I recall you disabled the ECO using the Autel scanner once. Did you try using XEntry? or need special coding to disable it?
One thing I noticed over the weekend, the Backup camera error is the first to post even if there is no shift error. I basically deleted all DTC's, check it was clear. Did some errands and recheck, Boom, backup camera communication error with ignition lock.
Separately, ,the shift issue happened again when ECO is active, but not ready to shut off the vehicle.
This thread title is about "the car throughs itself into P at low speed". Here we have a related fault "the Direct-Selector shifter doesn't work" - Two distinct issues but actually related.
We've seen how everythings get overwhelming pretty quickly because diagrams encompass entire production options with updates CAN E split > E1+E2. CGW getting merged into F-SAM.
It's an excellent exercise to understand how things work. It helps understand how they disgunction when they don't work.
What happened to Juan's W212 is the Direct-Select stopped controlling the gearbox shifter ISM while the ECU had no problem shifting to P, N. Meaning the path to ISM was proven functional... half the battle.
The broken path was from shifter to ECU. This is when I come forward to drop a nugget on our work bench....
There is something particular not scribed in the schematics we learned to rely on
misleading system diagramRead this block diagram to observe how things are connected.
cheapo basic shifter control
Shifter is a cheap dumbo circuit and SCM stack of PCB's is the local Lord hosting other peripherals that speak through it's I/F circuitry.
Not Splitting hair:
bad SCM module,
bad GND supply,
both combination
Unless we scope the frames that cause havoc to the timely work of VIP modules, we are not going to know exactly the cause of soft-crashes SCM Coms. I found easy to bring Benz electronics quality up to basic Japanese grade.
Plucking the Lemons out :
The shortcut I have selected is to fix both sources of engineered troubles. Unexpectedly this has payed off with ECU-TCU working seamless shifts like a machine gun. Both ECU and TCU now work totally awesome unlike when SCM floods ECU with retransmits.
Golden Easter Eggs...:
The engineered defects Benz carefully bakes for decades are easily managed and removed in other iteration of chassis, markets variant.
This body of knowledge by team Surya-Cali-Juan will help fund a rewarding getaway trip for many forum participants.
Enjoy.
Not sure if you have seen this failure mode for the SCM
I understand there are 2 manufacturers for the steering column for MB: Kostas, and Valeo. Here is a video for another platform with similar but not exactly same module
I understand there are 2 manufacturers for the steering column for MB: Kostas, and Valeo. Here is a video for another platform with similar but not exactly same module https://youtu.be/vzrW4HEXdVo
Notice for that platform, there is Valeo, and Valeo modified with a protective ring. Protection from what?
SanJuan, you've found great source of interesting material.
I could sugar coat things to the point no one understand how to make Good Benz better - For free courtesy of MBWorld dor org forums - Home real enthusiasts!
👏
- The first guy took apart its SCM and soldered a good NC holder. In fact ... disconnecting the SCM sandwich solderless junk and connecting it back restored/cleaned the poor connection... "No more, No less" as says Master Tasos. nothing wrong with that big corner solder joint.
A1 corner-connection used as holder.
> As for YouTube video:
Watch it over and over to realize how well these excellent cars are built for premium repairs.
The grounding ring and grounding spring they're adding is a useless mascarade...
MB carefully builds painted GND screws and unsoldered connection pins for decades, it's not to give away the golden egg in a simple TSB.
Instead of fixing know existing active problem, they go out to fix a non existent problem... ungrounded column: not a problem!
The PR campaign is "We don't know, our teams are working very hard"...
This engineered electrical chaos is on par with :
The twisted squeaky wipers
The dry slider pins that overheats disks
The splitting vinyl seats
The amazing oil leak into CPS harness
.... fill in your favorite money maker
Lucky us every one of these planted Easter Eggs are easy to fix to then drive the best German vehicles.
The MbWorld team helps deliver wisdom to the wise: loose the Easter Eggs ASAP.
😎
Last edited by CaliBenzDriver; 01-30-2023 at 04:21 AM.
@S-Prihadi I recall you disabled the ECO using the Autel scanner once. Did you try using XEntry? or need special coding to disable it?
One thing I noticed over the weekend, the Backup camera error is the first to post even if there is no shift error. I basically deleted all DTC's, check it was clear. Did some errands and recheck, Boom, backup camera communication error with ignition lock.
Separately, ,the shift issue happened again when ECO is active, but not ready to shut off the vehicle.
Yes, I killed ECO using Autel as I got Autel first before Xentry Passthru. https://mbworld.org/forums/e-class-w...ging-algo.html
However that the ECO button still shows green or dead when I pushed to OFF it, but the button is now useless....which is good. Not the most elegant way to kill ECO, but I got what I want.
What I am saying is, I can not disable the ECO button LED light hahahah, but the ECO function I was able to kill.
The Instrument Cluster no more has ECO label whatsoever, case closed. So I never bother anymore with Xentry.
TO NOTE :
Even with ECO disabled by coding/Autel, the charging yoyo will still exist as long as the LIN is still connected to alternator as charging profile is controlled by ECM and not ECO algo.
ECM charging profile can go to the brutal 14.7V as high. Too high for my liking.
LIN disconnected, which means alternator own voltage and current regulation at work without ECM interfering..... never hit above 14.1V, which is good.
Juan wrote : Separately, ,the shift issue happened again when ECO is active, but not ready to shut off the vehicle
At least we have some new information here....good.
The image below of May 2021 where Q-Diode OPEN/disconnect by its own algo when ECO has not been disabled by coding/autel ( Aug 2021 ), but I turned it OFF using the button.
It is maybe a self test feature to measure state of health of baby ECO 12Ah battery. What I mean is, behind the scene the ECO algo will do its own operation with Q-Diode and K114 relay of ECO 12Ah battery, even before ECO is ready to use or turn GREEN.
I been looking at N73 EZS wiring diagram and ISM A80 and it is disturbing, because it was not updated to represent facelift model with B03 option using baby ECO 12Ah battery at the trunk.
My naughty WIS-ASRA is a 2020 version, so a 2014 - 2015 cars should be included to the latest updated information...but unfortunately I seen weird mistakes on WIS wiring for facelift models.
ISM A80 information : But of 2011 and I can not find newer ones to describe how is a B03 option model then get the equivalent additional battery G1/7 via N73 ? G1/7 is the small 4Ah battery hidden inside the dashboard.
Our B03 option baby ECO battery of 12Ah is called G1/13
No newer N73 wiring diagram. Below is the only one :
pe54.21-p-2104-97daa, Wiring diagram for electronic ignition lock control unit (EZS) Page 1 of 1 Model 212 Control unit N73
One more thing :
Before I completely remove my baby ECO battery the 12Ah, its internal resistance was in the red and was 2,550 milli-ohms and supposedly SPECIFIED VALUE is to be below 1,500 milli-ohms, BUT I never get the warning to replace Auxillary Battery.
Since I never use ECO-S-S feature, I simply ignore that fact.
Battery Internal resistance 101 : https://actec.dk/media/documents/68F4B35DD5C5.pdf and https://www.hioki.com/sg-en/learning...esistance.html
The higher the internal resistance of the battery is, the less power/amperage the battery can deliver.
My thought and worry for your current issue maybe massive voltage drop as possible priority suspect. Yes, cleaning those grounds you have not done, must be done......... BUT I am worried of your ECO 12Ah battery at the trunk.
Again I have to emphasize that : ECO-S-S .....as part of its working algo, does at certain interval OPEN/disconnect Q-Diode when not in engine-STOP mode yet.
Most likely as voltage investigation for ECO 12Ah battery..maybe. I proved this is so as you can see at the above video capture.
So we can not assume that ECO 12Ah battery will only be in use during engine-STOP mode at say a traffic light, when ECO-S-S wants engine to be in STOP/SLEEP mode.
Best you also clean and check tightness of ECO 12Ah battery connection and including the one at K114 relay.
Remember, your alternator yoyo downward voltage is adding misery if not mystery..... to your current issue, when and if we suspect low voltage as the cause.
How old is your ECo 12Ah battery and what is its internal resistance now as per Xentry ?
Damn, I been driving for so long, I did not realize there are two soft/mild clicks for NEUTRAL , I know how to tap softly for Neutral but did not realize 2 separate clicks are there.
Damn, I been driving for so long, I did not realize there are two soft/mild clicks for NEUTRAL , I know how to tap softly for Neutral but did not realize 2 separate clicks are there.
Honestly, I have even monitored myself about how I move the lever. That is, do I shift firmly or softly creating a "doubt in the click" for the computer? Sometimes I feel I move the level too fast in either direction and blame myself for not waiting for the car to engage, i.e. a 1-sec pause for the car to realize I click it.
At some point the victim starts to blame him/herself,
When power and ground and CAN BUS distributor all good and clean........ but trouble still exist :
You realized that eventually you need to closely inspect the N80 SCM.....aka let your delicate fingers open it up to see possible loose wiring or whatever, as Cali suggested.
Looking at the Direct Lever stalk and the message of it being MAILFUNCTION
My N135 board is also part of the N80 SCM, just like the S16/13 Direct Select Lever.
However, the N135 board is a bit more complex and uses LIN to speak to N80 motherboard and N135 on its own, have some sort of simple microprocessor.
The good thing is, the DOWN PADDLE switch of N135 board which went intermittent-ly bad on me, was somehow categorize as 1 component of N135 and can be identified as DOWN SWITCH DEFECTIVE.
S16/13 is directly part of N80 motherboard and seeing those 6 transistor or logic gate ( the 3 pin ones ) on the PCB board and knowing the Direct Select Lever is a 6 position switches ,
I think N80 is not able to ascertain of 1 bad switch or bad transistor/logic gate ,
and therefore : if any status-signal coming out of S16/13 when deemed as "wrong" by N80, the N80 simply declared a MALFUNCTION of S16/13 as a complete assembly and triggered a PARK mode.
S16/13 I am sure is not using CAN BUS to communicate to N80 motherboard, but rather some sort of status signal. I don't know the correct electronic terms to describe it, sorry
==============
Why don't you do the "hammer" test on N80 module to see if any bad contact exist from loose connection.
Get car engine running and gear in D, apply brake. And start applying impact to N80 body using your hand and do fast switching on direct lever stalk too.
While at it run the Xentry in a mode to observe voltage into N80 and if possible state of S16/13 actuation. Use screen record program to record Xentry.
In my case of intermittent bad DOWN PADDLE SWITCH, it was totally electronic issue and not a loose mechanical contact.
I wonder if the transistor/logic gate used by my DOWN switch can "leak" and created an unintended actuation. I know transistor can "leak".
However since my DOWN PADDLE SWITCH is not a master device like S16/13, I managed to make the DOWN PADDLE SWITCH to be triggered into safe mode or make it being ignored by N135 processor's by
short-circuiting the mechanical switch. When the N135 board saw the switch in always a CLOSED state, it eventually ignore that switch existence and I still can drive the car without worrying a downshift occurring on its own.
I also actually short circut the UP PADDLE SWITCH too at the same time for safety reason. There is some beauty to this "soft/electronic" switches in terms of safety.
In your S16/13 case, I believe a NON-ACTUATED state does produce a constant signal , and the S16/13 must send to N80 processor that signal as a READY STATE information ,
as part of N80 safety design to know S16/13 is actually working, when in rest position. I hope some electronic engineers can chime in on this and explain to us better
==============
If you want to simulate low voltage scenario to N80, when and if you see the amperage at instrument cluster shows zero amps and voltage close to 13V aka main battery is OFF-LINE and baby ECO 12Ah is in charge,
perhaps there then you can spin your steering wheel from max LEFT to max RIGHT many times to drain the ECO battery, while also in D engine running and brake HOLD. See if a low voltage will trigger PARK mode as safety measure.
gf27.10-p-3029ahl, Emergency-P function
In emergencies, if for example undervoltage prevails in the on-board electrical system or the communication with the intelligent servo module for DIRECT SELECT (A80) is faulty, the emergency motor in theintelligent servo module for DIRECT SELECT is powered by the additional battery (G1/7) via the electronic ignition lock control unit (N73) and
thereby triggers the emergency P function.
I modified the WIS document to remove/slash-out additional battery out of the explanation. Basically the logic is, if low voltage if occurred, PARK will be engaged as part of the algo does make sense.
> Paddle trouble:
Do you still have your failed paddle swich board ?
Have a look at it's simplicity. The control electronics are grouped on the steering wheel main PCB.
The switch is so over simplified that you can easily conclude what's going on by looking at it.... Can you spot anything suspicious on paddle board??
> Shift to Park after Pyro Emergency:
The power emergency of loosing ALT & MAIN is created by blowing pyrofuse and ECM shutting down engine after a crash. We learned that F-SAM has accelerometer built-in to sense crashes. conditions (in addition to data the SRS module can volunteer).
How to shift into P without power... use a spare battery named AUX!
1-- Tiny dashoard Aux is for post pyro P-shift only.
2-- Faty trunk Aux is P-shift plus car power during ECO restarts.
3-- Farad caps Aux module works like an AGM but dies much faster 🤪.
I don't think MB added all that complexity to supply power when Yoyo game drains Main battery in 11V territories. However it appears that AUX does chip in power while ALT itself is busy wasting Main AGM (No code right? 😳 .
The outcome is AUX gets wasted as well with extreme drain/charge currents. The code refers to "high internal resistance..." ie. reduced voltage output through internal drop by high-R.... bad!
From the above explainations we understand why no one should do away without good AUXILIARY power unit (SLA AGM Battery or oversized Farad Capacitors).
[ people with premature AUX-Capacitor module in codriver footwell are great candidates for Yoyo drain game! Farad caps have one extreme punch, just not many.]
Last edited by CaliBenzDriver; 01-31-2023 at 05:58 PM.
Yes, I still have the N135 board. But me too lazy to mess with it again.
I also have M271 EVO engine computer which I intended to rip open but never did.
Cali wrote :
The power emergency of loosing ALT & MAIN is created by blowing pyrofuse and ECM shutting down engine after a crash. We learned that F-SAM has accelerometer built-in to sense crashes. conditions (in addition to data the SRS module can volunteer).
In the older model with pyrofuse inside the F32 ...yes this is true.
With newer model or any model where pyrofuse is at battery positive post, pyrofuse only kill the power to starter motor M1, that is it.
Busy with other things (work), the car has only done once more so far, and I am nearly certain I did not click up (reverse) firmly when it happened. Now I am certain I click to the end, and wait while shifting between D->R->D.
I will be working on it in the next few weeks. In the meantime, I got a used steering control module as a patient for practice before I disassemble mine .
As an update, about 2 and a half years after giving my EIS a thorough cleaning, the behavior came back. Yesterday I opened the module and soldered the solderless pins. It would make perfect sense that this was the issue as three of the pins connect to the copper wire wrapped around the key cylinder. Fingers crossed and I'll post any updates I have.
As an update, about 2 and a half years after giving my EIS a thorough cleaning, the behavior came back. Yesterday I opened the module and soldered the solderless pins. It would make perfect sense that this was the issue as three of the pins connect to the copper wire wrapped around the key cylinder. Fingers crossed and I'll post any updates I have.
.. Please keep us posted.. As I mentioned earlier, I have a "patient part" to practice on the soldering of the "Steering Column Module", and plan to do the EIS as well. Also, a new to us ML350 so I can take it easy while I work on the E . I have been indisposed because doctor's order not to lift weights nor not trivial bending positions , which are required to get either of those modules out. Hopefully, I get the green light by the end of June.
01-27-2023, 01:27 PM
..... to your current issue, when and if we suspect low voltage as the cause.
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, which are required to get either of those modules out. Hopefully, I get the green light by the end of June.
