nice

 

I hoped that opening my ECU would show some components I could correlate to that image so that I would be able to answer the "on which connector does pin 45 live?" ....but, alas, no silkscreening and no chips that show where pin 45 on either connector leads. The trace appears to be burried.

Man these things are a PITA to open up!

 

you deserve it

Now enjoy the Bosch ECU fine tuning its timings and fuel maps to empower best throttle control.

 

The circuit board has 4 or 5 layers... next to impossible to trace connector pins.


power cleaning choke
This choke can get in trouble given bad conditions (vibration + heat + current ripples + mileage)
Samething for the tall caps...

Nice stable clean 14.1V is a positive factor for our chassis electronics.

 

Is this the plug? M272 e300

 

yes it is!
Confirm yours is a single wire connection, right?

Now double check your IC-Display does show the intended result: 14.15V

 

So I got curious... How does ALT-LIN affect the SAM counter (you know, the one you reset when changing the battery to a new one) as now it is allowing the battery to be charged to 100% instead of 80%?

 

Stock battery mgt is different according to how the distributed control is implemented on each chassis and what type of bugs plague it. Many 3rd party modules interact with the Bosch F-SAM+ECU.

In w212 the AGM voltage drop is measured during crank to gauge the battery health (internal resistance). That data feeds into the ECO logic if battery is presumed compliant with deep power cycling.

While ALT-LIN is disabled, I think we couldn't care less what ECU thinks about the battery status because ECU no longer has any dynamic control over AGM charge.

 

Mas Prakersa,

As per your PM to me, here is the LIN wire color for M272.9 3.0 Liter E300 based on your VIN.

It is supposed to be a single wire BLACK color, 0.75mm size.
Your engine is M272.952 M30, M30 means 3 liter, not the 3.5 Liter like US version.



Below is from ECM to Alternator




N3/10 means ECM, engine computer
G2 means Alternator
M1 means starter motor
G1 means the main 80Ah battery at engine bay.
F32 means Prefuse Box F32 near your battery..
N10/1 means the Front SAM fuse box and computer inside it. It is at driver side, near brake booster in engine bay.
N2/10 means the Rear SAM fuse box and computer inside it at the rear trunk RIGHT side.
B95 means the small battery sensor at battery negative post/wire, made by Hyundai





01. Show us the voltage and amperage on the Instrument Cluster when you have LIN unplugged.
02. Show 01 during COLD start, video will be better, 1 minute. RPM in view too please.

03. Show 01 during HOT* start, video will be better, 1 minute. RPM in view too please.
*Remember I told you in PM the unique behaviour of M271.8 alternator when LIN is disconnected, where engine has to achieve 1,000 RPM approx for alternator to start
working/charging and after that it is OK to be at low idle 650-750 RPM. Yes, alternator has minimum speed for it to be triggered to start work.
Perhaps the M271.8 alternator has bigger pulley than M276/M272 , as to not load engine much during low idle, hence its alternartor spin slower than M272/M276
Smaller pulley means it spin faster, but will cause more engine load.
I need to make sure your M272 is NOT like M271.8


Your car is a 2009,. so today near 16 years.
Please clean the hidden and un-documented ground wire under the car and the one near the main battery ( near suspension tower ) .
Read this : https://mbworld.org/forums/e-class-w...ital-wire.html

Check your F32 for tighteness on all its terminals no need to tear it down, if I were you now at 16 years old your car is.

Your F32 is bit different to mine below, but the concept is the same. Cleanliness and tightness




B1 is to/from battery
MR8 is to/from alternator
IM1 is to Rear SAM , not via K2 relay, always HOT , has power all the time.... known as Circuit 30
IG1 is to Rear SAM, via K2 ( switched by K2 relay ), known as Circuit 30g.
MR7 is to Front SAM , not via K2 relay, always HOT , has power all the time.... known as Circuit 30
MG2 is to Front SAM, via K2 ( switched by K2 relay ), known as Circuit 30g.
MR6 is to Front SAM, not via K2 relay, always HOT , has power all the time and this is for one of ECM power supply known as Circuit 30z. ECM has 5 fuses supporting it directly and in-directly.

Others goes to radiator cooling fan, HVAC blower fan inside the car , ESP/ABS and Electric Power Steering and etc etc depending on model year and LHD or RHD car


Have fun.....

 

Yes, single pin

 

Surya, thanks for thedetail
I will do my homework soon 👍

 

OM651 also suffers from no charging with the LIN disconnected. A blip of the throttle is all it needs to start charging afterwards. I will confirm later if it indeed needs to be above 1k rpm to trigger this alternator. Negative terminal has been cleaned.

 

I did the reboot today and, contrary to what I was expecting, I could tell a difference. Responsiveness was good and shifts were nice and consistent. I know something changed because my instrument cluster changed the main view. The normal view is to have the gears up top and the temp and time on the bottom. Immediately after reconnecting everything and starting the car, there was a view with the gear selection on the bottom and the temp and time on the top. But upon restarting the car, the view returned to "normal". Weird!

Nothing else seemed to have changed. My tranny had been shifting fine before, but it was just different after the chassis reboot.



Normal view. Temp and time on the bottom. Changed (temporary) view. Temp and time up top.

 

Now your ECU really has the pulse on things.
No numbers necessary...
Just results!

 

Good info, thank you.
Please update us on what RPM will start to trigger alternator operation.

 

ALT is absolutely not a battery charger
it is a power supply....
I don't see how an alternator may be disabled at any time.

Do reboot the chassis during this procedure.

At any rate THIS IS EXACTLY WHY WE TEST THINGS OUT... so good job for that.

 

Its not alternator being disabled Cali, it is too low an RPM during HOT start, which alternator-RPM minimum operational speed is not achieved yet and thus it wont produce power output above battery voltage.
This is called CUT-IN speed



If pulley ratio is say 2 to 1 , at 650 RPM- engine = 1,300 RPM alternator
Ratio 2 to 1, at 1,000 RPM engine = 2,000 RPM alternator

If ratio 3 to 1 , 650 engine = 1,950 RPM alternator

==================

Hot start = low rpm. Once the car moves, its okey, 1,000 RPM-engine or more surely happen.

COLD start = high engine rpm for a fews second like 1,100 to 1,200 RPM-engine, thus alternator immediately produce power within 2 seconds.

Thus we need more variant of engine ( and its alternator pulley ratio ) to participate in this ALT-LIN disconnect database.


My friend W204 C200 M271.8 been having its LIN disconnected 2 years now. So I know whats happening.

 

MS! if ALT is not sustaining the chassis power at idle has nothing to do with ALT-LIN being unplugged, yes?

You've showed that if you under-rev ALT you can reach its lower output limit.

But ALT produces like 80Amp at idle​​​​​​.

if you don't overload the chassis with 100A it works perfect to regulate load voltage at idle.


big cat ride to Macao, CN.

 

True, but maybe a LIN connected one can do earlier or lower RPM to operate, we do not know the actual cut-in speed of M2721.8 or OM651 alternator.
Surely we know our M276 does not behave like M271.8

Another example, only LIN connected alternator will do dumb-azz 14.8V, while LIN disconnected will never exceed 14.1V. This is for my Valeo.

 

yeah true, MS!

We do test the reality to double-check our expectations... and discover this or that in the process.

BTW... the ALT-LIN procedure does start with a battery float so that tired drained batteries start in good shape instead of low.

 

Update on this -- I just used a hex-prog to clone a 2nd ECU so I could have a plug-n-play stage 1.

While doing that I inspected the female end of the harness more closely to see if there were any clues about where ALT-LIN lives (according to the schematic) -- specifically, which pin45 is the owner.

Hilariously, neither connector has pin45 even populated - so that's not the right location on a W212 E63... back to square one I guess.

 

Quad,

Ur engine is M157 correct ?
The LIN is at connector M, pin 71 if M157 and not pin 45

 

And we know it's the larger connector since the smaller one only has 58 pins.

 

You. Are. Awesome!

Now I just need a way to disable that pin without breaking anything... maybe an epoxy or mylar coating... hmmm

 

Now that MS! has identified exactly what wire this is, install a toggle switch or simply cut it inside back cover: done!

I'd leave the fragile connector pins alone. 🤞