Yeah, that's my "plan A" -- the problem is that the large ECU connector looks pretty complex to disassemble without braking a whole bunch of tabs. But, I'll give it a shot this weekend.

Thank you so much for providing this schematic!

Is there any indication what color the line is - as a form of confirmation once I'm in there?

Ok - line on pin 71 cut in a semi-permanent way... that wasn't nearly as bad as I thought it would be

First drive was a success - but, as can be seen on the schematic, removing the ALT-LIN at the ECU also disables the oil level and temp sensor. This, in turn, will prevent me from being able to use launch control... and I can't tell when the oil is >= 176F in the AMG menu, which is important to know so the engine doesn't get pushed before it's ready... so, cutting at the ECU might not be the right move and I may reconnect it...

What year is your car again? I have the AMG Menu modification from @BenzNinja which basically adds the menu to the IC for non-AMG cars. It shows oil, coolant, and transmission fluid temps.

> IF /THEN /ELSE:
-- If cutting ALT-LIN at ECU disables B40 LIN oil sensor...
-- then you have to find the splice location and cut down that branch....
-- else lower near ALT.


G2 ALT-LIN C1 branch cut from B40 OIL-LIN C1 splice

It's a 2014 E63. If you you look at the schematic, it makes sense why the oil sensors were affected when cutting the line at pin71.

Yeah, I'll have to figure out a way to get to the back of the alternator

yes, serial LIN stands out as a shared control line.

It reads yhe oil sensor and also instructs ALT all at the same time on the same single line.

yep, that was my way of doing it on 276-NA

At least now you can be sure ALT-LIN is a proven MOD to help your M157 run right.

This picture (from Starfinder) may help.

@QuadTurboPrius what is your full model designation? 212.XXX? Or VIN.

Thanks JR!
this is the right way to locate that LIN splice where ALT branches out from oil sensor LIN.


The actual splice location may not be more practical with any better access than alternator rear connector

QTP... in case you have missed JR! test report:
REBOOT + FLOAT steps are recognized effective in addition to ALT-LIN.


The ECU/TCU computers enjoy simple Rx. It helps get the wonky CAN networking better bandwidth out of CGW that ECU/TCU unfortunately depend on a lot.

Oh boy I have lots of catching up to do.

Confirmed 1,000 rpm is the trigger to start charging for OM651. If I do a light blip under 1k rpm nothing happens.

I must have missed it but what about ICE engines, at what RPMs does it start charging? For example, M272, M274, M276, M278 etc.?

M276/8 Valeo fixed pulley ALT supplies 100% chassis power at 650Rpm idle.

That's about 80Amps under fixed well regulated voltage.


> LIMITS OVERLOAD at low Rpm:
Outside of stock load, voltage drops off unregulated as shown by MS! testing.

Exceeding load limits may happen under ECU control or self-regulation (ALT-LIN or ECU-LIN).

> STAY WITHIN SPECS:
You can not both overload the generator AND expect regulated power at 500.Rpm!
This creates a dangerous spikes factory.

So the long story short is don't add power angry accessories. They can overwhelm chassis generator near 100Amp

Good and important info, thanks
If I may know your VIN, I want to check if this is because of a typical Valeo alternator, or because your alternator has AOP pulley. Overunning pulley.
AOP pulley is being discussed here : https://mbworld.org/forums/e-class-w...ml#post9118647

The AOP pulley P/N for my friend's M271.8 is below : ....................NOTE : A646-xxx the older P/N , there was a diesel engine OM646




The alternator for M271.8 is below : 150 amps valeo

Oh yay! This is true for both ALT-LIN unplugged and plugged in right?

yes it is.

Sounds good.

I didn't see this until now - Thread is too busy

It's a w212.076

VIN: WDDHFOEBOFB153234

Pulley is fixed/solid piece



From Valeo:

No accessories are on