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Bill, Chevy Technician
Category: Chevy
Satisfied Customers: 1776
Experience:  GM Certified Master Technician
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I have a 2006 chevy silverado 2500hd with a 6.0 gas motor, I

Customer Question

I have a 2006 chevy silverado 2500hd with a 6.0 gas motor, I have been getting p1516 code on and off for about two years and I have replaced the throttlebody twice,harness to the throttle body,control module,throttle pedal and yesterday got the ecm reprogram
and still the p1516 came on and just recently was getting the p2135 code and they are both related to each other because the truck will go in limp mode when this happens. I have checked grounds and everything and I am stump on this problem. One mechanic told
me I should have soldier the wires together for the throttle body harness which I just butt connected together and thats it.
Submitted: 2 years ago.
Category: Chevy
Expert:  Bill replied 2 years ago.


He's absolutely correct. Those circuits should be soldered. They are very sensitive to voltage fluctuations and a crimp connection can build microscopic corrosion called fretting. One question.. which module did you replace? The engine controller or the tac module?



Customer: replied 2 years ago.
The harness was not bad I just changed it becasue I had it, I changed the tac module.
Expert:  Bill replied 2 years ago.

I would recommend removing those splices and soldering the connections. That being said, the most common cause of this issue which is often overlooked is the connections at the tac module. Again... the connector "fretting" I was referring to. Remove the tac module connectors and plug them in 3 or 4 times. This cleans the contact area. Then load up the connector with dielectric grease that is available at any auto parts store.

That should take care of it.


Customer: replied 2 years ago.
Okay, I will try this today and I will let you know tomorrow.
Expert:  Bill replied 2 years ago.
Sounds good.
Customer: replied 2 years ago.
It did not work today I was driving to work and I got two blocks and it came on the p1516 code