Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
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?
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.