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2010 ML350 Bluetec Replaced alternator but it's not recognized
Hello. New day, new problems with this truck.
Water pump gave out and leaked coolant all over my alternator while I was driving and fried it.
I've replaced the water pump now, but having difficulty getting the replacement alternator to work.
First, I cleaned my fried alternator with QD electronic cleaner and reinstalled it. It didn't work. Scanned with DAS and got the following code:
109B00 - Component N3/30 received no LIN message from component G2/7 (Stored/current).
I figured maybe I cleaned something that shouldn't be cleaned and now the alternator isn't being recognized or something.
So I got a replacement alternator and installed it. However, it isn't charging either and the 109B00 code is still showing as stored/current.
I then wondered if the connector was faulty, but not sure how to check it. But when I examined the connector, I noticed it only has one copper on one side... is it supposed to be like that or are there supposed to be two? I've attached a pic below:
As you can see, the left side is empty while the right side has copper. Is it supposed to be this way?
I used a multimeter to check the voltage of the copper side of the connector (left side in the pic) and I got 12-ish volts, which was same as the battery.
Does anyone know why the alternator wouldn't be recognized? Any help please... this car is driving me nuts!
Thanks.
Last edited by SpikeJones; Sep 8, 2021 at 04:02 PM.
Technology change those years on weekly bases, so what was principal a year ago doesn't have to be today, but classic wiring for alternator with build-in regulator is 1 heavy wire for charging current and 1 smaller wire for battery voltage to activate the alternator.
Meaning 1 prong is what it takes on the plug.
2010 models don't have SCN coding, so I have no idea what can be recognized, or not.
Most likely the alternator is faulty.
It's easy to get alternator mixup with these cars.
If you are getting missing LIN bus message errors, it's either because 1) the voltage regulator is toast, on the bad/original alternator or 2) the new alternator is not of the correct type, and is setup not to use LIN bus.
This alternator frame is common to multiple applications.
With your car, the LIN bus is how the ECU communicates with your alternator. ECU tells alternator to report output voltage and load. ECU can tell Alternator Okay, enough for now.
All in the name of getting best fuel economy, and not overcharging the battery.
In my opinion it seems like this slightly undercharges the battery rather than let voltage regulator push for a perfect charge state on it's own.
But not all applications use LIN-bus-type voltage regulators.
Long story short, be sure you have correct replacement alternator unit.
It's also possible to find the exact replacement voltage regulator and brushes to rebuild, but you have to be very careful with cross-referencing and making sure of your sources.
Many will say 'only Bosch reman!', but what if OE on your vehicle was Valeo?
Mine was, and original unit lasted 11 years. When I finally replaced it I got a reman which was mismatched. Then found a NOS Valeo unit at Stockwise.com. (overstock).
Thanks a lot for everyone's input. Here's the update:
Apparently the replacement alternator must have had the wrong voltage regulator or perhaps it was just the wrong unit altogether.
When I opened and cleaned my old alternator, it seems I forgot to install one of the screws to the voltage regulator. There are around 4 or 5 of them, and they all serve a purpose. Each screw makes contact with something that has to do with voltage... in my case, I believe I failed to reinstall the B+ screw. For anyone who may take apart their alternator for cleaning or parts replacement, just know that every screw on the voltage regulator serves a purpose. They look like they're just there to hold things down, but they're there for more than that.
Anyway, I took my old alternator to a guy that repairs them and he showed me that missing screw right away. He also did some work on the diodes. I reinstalled it and the charging system is back to normal. So far, so good.
As for the one prong connector, that's how it's supposed to be.
Thanks again for all the input guys. Very much appreciated!
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