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Daniel Wilson
Daniel Wilson,
Category: Medium and Heavy Trucks
Satisfied Customers: 5558
Experience:  Owner at DJ Wilson
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I am working on a 2006 GMC C4500 with a LLY duramax. The

Customer Question

Hi, I am working on a 2006 GMC C4500 with a LLY duramax. The customer brought it in for a check engine light and I have no communication from the ecm to the tech 2. All other modules communicate fine and the transmission has a code for ecm communication. I am looking for guidance as well as wiring diagrams for associated systems. The GM body builder website has been of little help. Thanks
Submitted: 1 month ago.
Category: Medium and Heavy Trucks
Expert:  Daniel Wilson replied 1 month ago.

Hi Jared. My name is***** will be glad to help. Check the wiring harness and connector pins at the ECM for any corrosion or damage that might cause an open circuit for the ECM and if okay verify the power and grounds for the ECM. If they check okay I recommend having the ECM tested or if you could obtain a test ECM if possible as it would lean towards a faulty ECM. From the sounds of it you likely have the schematics already?

Customer: replied 1 month ago.
I do not have the wiring diagrams yet. I tried the GM body builder website with very little success. I would like to get the ecm pinouts and the diagram also if you have access. So far no success and upon further inspection, found out the engine was replaced with a remain long block. Sloppy replacement to say the least as morr bolts seem to be missing than present. Wiring is all over the place so a ground distribution diagram may be helpful also. Thanks
Expert:  Daniel Wilson replied 1 month ago.

Hi Jared. I have the full electrical manual I can offer for an additional service or would you just like individual parts such as the power and grounds for the LLY engine?

Expert:  Daniel Wilson replied 1 month ago.

Not sure why but I can not post the offer for you unless there are two responses from you on this chat page. It is how the site is set up. ill post the offer once there is another reply. It is 321 pages of schematics for this truck.

Expert:  Daniel Wilson replied 1 month ago.

Click on this link for the ECM connector pinouts I uploaded for you. Let me know if you need more info or help.

ECM pinouts

Customer: replied 22 days ago.
I would like to know why I cannot refund this answer. The 321 page manual offered is a free manual that I can get myself on the GM upfitter website. No charge on there. Also, the screenshots you sent are not even readable.