Wail maghazi

I'll try that. But i dont think it would make a difference, i only have little knowledge on how the system work but i could assume that, the Rear SAM controls the output voltage Through COM wire, and the main ECM detects the alternator voltage through DFM wire, so i dont think taking out the battery sensor would make a difference. But what if i unplugged both the DFM and COM wires

S-Prihadi

The Hyundai Mobius is a current sensing device, among other capabilities it can do.... I am guessing.
So in a smart power meter application, voltage alone can not be the basis of total calculation, amperage must also be calculated.
My thinking is, if say the loss of that Hyundai Mobius sensor will default the charging algorithm back to normal as in common charging 13.8 to 14.6V but no discharging <12.5V....., this can prove that maybe your alternator is not the pure 100% culprit.

Sometime a problem may possibly be caused by two event/error, not a single one.
It is a fast easy test, for now.

bmwpowere36m3

Attached is battery management for W212.0 / 2 up to Feb 28 2013. Within the document there are other date cutoffs for features and functions.

pierrejoliat

Interesting, what changes came after February 28th? Just curious as my '13 was built just after that date in April. Thank you in advance! I know my 212's are only one model year apart, but they work differently, I just don't really know how.

Wail maghazi

i dont know how i could repay you for your efforts sir, i really appreciate what you did. Thank you very much

Wail maghazi

you were absolutely correct, sir you're a genius.

bmwpowere36m3

So regarding the W212.0 / 2 up to Feb 28 2013, key points I see are:

• Minimum temp of battery for temp-specific charging (15 vs. 10* C)
• Alternator management target voltage 12.6 vs. 12.7 VDC (I assume they mean with minimal load)
• "Light " consumers target voltage 13.5 VDC (I assume they again mean low loads, but more than the above)
• With air conditioning ON and high blower setting target voltage = 14.3 V (don't know if its really only those two that trigger it)
• Special function, as of June 1st 2010, target voltage = 14.3 when alternator management is active, vehicle is stationary and front door/s are open

This basically shows the "charging" profile,

bmwpowere36m3

There should be three ways, assuming your car was built as of June 1st 2010...

• Workshop "mode", after battery management is active, stop the car and open the front door
• Xentry to enable mode or disable battery sensor
• Possibly just unplugging the battery sensor, the small electrical connector. Not the whole terminal, as the sensor is integrated into it.

bmwpowere36m3

To follow up @pierrejoliat here's battery management for W212 as of MY14. Looks very similar to the as of June 1st 2012 changes from the prior... regarding the fast charging, temp-specific, alternator management, etc... Would need to compare the consumer cut-off tables and other information as well.

Wail maghazi

Yes i unplugged the sensor, and under load I'm getting the exact same readings posted above, there was no difference, i guess now that means that my alternator is underperforming.

Wail maghazi

Main power cables have been checked, I'm going to do one last test and afterwards I'm ordering the new alt, what I'm gonna do is i will connect a 4mm cable between the engine and the negative battery terminal and see if the values change, if it gives me the same readings then case closed that's the alt, it could be the Alt or the Voltage regulator but honestly i dont wanna get a headache I'm just gonna order a complete new alt.

pierrejoliat

Thank you, extremely helpful, I guess they just tweaked it a little then, I was under the impression it was a big change, I've always wondered if this had anything to do with the different gas mileage I get between the two cars, one sport, 27mpg, one luxury 31 mpg.

bmwpowere36m3

To throw a final complication into things, when the car is in alternator management it can:

• Sets a lower voltage in exceptional cases (e.g. stall prevention, cold start at high altitude, catalytic converter heating)

I'll assume thats lower than either the 14.3, 13.5 or 12.6/12.7 depending. Unfortunately really complicated, ideally you'd what to know what the control module is commanding and then verify that output from the alternator. Then continue based on whether is agreeing or not.

S-Prihadi

Now, this is so good. Glad to have a true engineer on board ( BMW ). Thank you so much.
I also realized my WIS 2018 ebay bought is lacking of many so called FUNCTION documents, thank you again .

S-Prihadi

Power cable as in Positive cable.
Now you want to try to reduce ground resistance by giving a direct wire connection from alternator closest metal which is engine block direct to battery. Good call.
I have 2 suggestion, if easily do-able/accesible, use the alternator bracket instead so that you get a more direct path.

If I may suggest further, also if possible and when can be done safely, send extra cable from positive output of alternator to pre-fuse block.

I don't know the kind of crimping condition your alternator positive wire or..... it come with or without the soldering which I seen my car negative cable gets.
I have seen crimping "semi-failure" due to corrosion and reduced mechanical compression strength and only obvious when hot and/or when high amperage pass thru.

As for grounding connection, I have to admit MB is not stingy for these. I would rate it awesome.
My Ford Fiesta is so damn stingy for negative grounding cables.

On my car, the alternator set up. Should be similar cable location wise with yours. Good luck....

S-Prihadi

To make matter worse, the amperage we read on the dashboard under special hidden menu is the NET input or discharge of the battery and is not the total alternator output itself.

For troubleshooter, sense the positive wire from the alternator before it enters the F32 prefuse to see actual alternator output before any consumption by other components at F32.


Here are some examples : Red current clamp at positive cable of battery

Battery discharging. Ignition is position 2 ready to crank.


Engine started and alternator charging the battery and serving other needs aka in-house use. This is only a +80 seconds run from cold start of +-30 Celcius ambient temp

So engine management consume 31.x amps. No aircond or anything, only auto headlight low beam on





.
Current clamp position for alternator output



One tip....
If ever your cable IM1 , which is Prefuse 159 . Valid for front on-board electrical system battery (G1): Rear SAM control unit with fuse and relay module (N10/2)
is very close to car metal body like mine....no it does not touch car body yet........ use additional insulator as a safety layer.
Cables are good when its original insulator is still intact and I am fine with it running on car body.
When cable lug added and heat shrink applied like shown below due to cable lug must be a unique 90 degrees bend type and long,
that means the insulator protection value at cable lug to its crimping, is not as good as original virgin cable.
The 1st few weeks I got this car, that safety layer is the first "mod" I did



Happy troubleshooting Wahli....

Wail maghazi

I just want to notify all of you that my issue has been resolved by replacing the alternator, FINALLY after so much agony, i want to thank all of you for replying and directing me for the solution, and lastly i give my deepest gratitude and thanks for
bmwpowere36m3 and S-Pirhadi i dont even know how i could repay you guys thank you so much for the care and effort.

Wail maghazi

bmwpowere36m3 and S-Pirhadi if i came to visit the states one day, your beers are on me.☺

bmwpowere36m3

Glad you got it resolved.

S-Prihadi

Wail, Happy to hear case closed with happy ending and thank you for coming back to update the situation.

To me this is a unique case study because this is not a total failure of the alternator.
I guess we are seeing an aging alternator, aging in the sense of heat aged alternator not able to deliver 100% full power anymore like when it is new.
The question is, which part of the alternator is the one aging ? The semiconductor side of things like voltage regulator, diodes and etc etc....
or the mechanical side of things like worn out carbon at slip rings , insulation at coil windings on stator and/or the like.

Erbi Hakrama

Hello everyone,
I have a w212 220 blueeficiency with the same electrical issue as mentioned above, the alternator voltage reads 12.6, when i turn on the AC the car starts vibrating and the AC sometimes stops working just makes noise but does not blow, and 2 times everything electic on the car stoped working, headlights, windows, cabin lights, ac, heated seats, pasking sensors, even the steering wheel electrical motor stoped working the steering got hard like the car was off.
When i turned the car off and back on, the check engine light was on, when i scanned on the OBD reader, there were more then 50 fault codes stored, on everything it said “Supply Voltage Too High”
Now please if anybody has had this problem and fixed it, reply to this message because i dont know what to do.

Thank you,

S-Prihadi

Blue efficiency cars are the worst for alternator management. My friend's W204 same engine M271.8 EVO is a Blue Efficiency.
I hope you only have issue with the alternator or its voltage regulator and nothing else.

The engine computer aka ECM will coordinate increased RPM whenever AC compressor is turned ON, as the load is high for and engine at idle.
Usually increased RPM by 100 gross and then AC compressor loading it, NET you get 50 RPM extra engine RPM at warm idle when AC is ON, compared to AC OFF.
The smaller the engine, the more it suffers from AC loading, as small engine has less low RPM torque than say the 3.0 or 3.5 liter engine.
This is based on healthy AC compressor. If you AC compressor is not healthy, it will offer so much resistance and that can make your engine idle so bad aka too low.

Your alternator is LIN controlled by the ECM to do its dumb-azz low charging level....but when headlights are ON and the AC fan blower at MAX speed, the charging voltage will go up 14.x volts usually as
the engine knows you need more amps. Try this while at idle and at 1,000 RPM, if voltage does not go better than 13.6V, your alternator is a big suspect.