Nobody knows? should I pull hard to get it off directly?

 

Here is the some info from the manual.

I think you will have to insert something into the slots on the top to release the locks somehow.Just guessing.

 

Any luck?

 

Yes. With your tip and this video, I did it.
https://www.youtube.com/watch?v=3ZFohdSalxA
It's easy. Just use a screw driver to lift the locker (white part) from bottom and pull the connector out. That's it.

Today, I've replaced #6 injector and coded it with Rheingold successfully. But the problem still there. So it's time to figure out how to check injector electronic wires.
Here is Rheingold test plan
Plan to unplug #6 and #5 injector wires to check if I got 'open' or 'short' circuit. For thinking more about wires.

 

Yes that's a good plan to remove the injector plug and check the code.How is your injector resistance?

 

Old one and new one are the same, 180k. I replaced it in hope of the old one is bad even with normal resistance. Actually, I'm wrong....

 

Diesel Injector Engine M57N2

I am very thankful Nimja.:thumbup::thumbup::thumbup:
See attachment for resistance.

 

Yes - but along with checking the injector resistance you must also check each pin for a short to grd to the injector steel housing.