Back on the search for another wire. im looking for the pulse/speed wire on my 07 topkick . I have went through gm upfitters and located it mid frame on the passenger side, its says its a blck/yellow wire. The question is, is where is it located under the hood. i tried to follow it but without ripping apart the factory harness is next to impossible. i tried to descipher the gm upfitters schlamatic but i cant figure it out. Can anyone please tell me what harness and wire color or even pin number of were i can find this thing under the hood.


thanks in advance

Which page of the PDF shows the wire you describe.

Brian

Check the C section on the engine you have. C2 connector of that engine pin 54 is a yel/blk wire for speed signal. This may be where it is going. Compare circuit number on that page to the page you were looking at.

Brian

Check the C section on the engine you have. C2 connector of that engine pin 54 is a yel/blk wire for speed signal. This may be where it is going. Compare circuit number on that page to the page you were looking at.

Brian



my truck has the lmm motor in it.

where is that c2 harness located at. there so many harnesses i dont know which is which.

The C2 is the plug on the ECM. I do not know where the ECM is located on the medium duty trucks. You can look at the images in the pdf on the gmupfitter site of the plugs. There is a C1 and C2 on the Bosch ECM. As to what the ECM looks like you can goto here and open this pdf file and it will show the images of a LMM ECM.
http://download.efilive.com/Tutorials/PDF/Bench%20Harness%20Tutorial.pdf

Brian