W211 E350 2007 secondary air injection pump problem
Thread Starter
Newbie
Joined: Jan 2026
Posts: 2
Likes: 1
W211 E350 2007 secondary air injection pump problem
After my car's ECU failed, I replaced it with a 2008 model unit. Subsequently, I noticed that the fuse for the Secondary Air Injection (SAI) pump was blown. I replaced the fuse, but it blew again immediately upon operation. However, when I disconnected the electrical connector from the pump, the fuse remained intact.
Is this issue caused by a software/programming error in the new ECU, or is it a mechanical/electrical failure within the pump itself?
Furthermore, do you recommend repairing the pump or replacing it entirely?
I am considering dismantling and inspecting the pump, or performing a resistance test as demonstrated in the video.
Is this issue caused by a software/programming error in the new ECU, or is it a mechanical/electrical failure within the pump itself?
Furthermore, do you recommend repairing the pump or replacing it entirely?
I am considering dismantling and inspecting the pump, or performing a resistance test as demonstrated in the video.
