Real-World Repair Story: The Phantom No-Start
Real-World Repair Story: The Phantom No-Start
I remember a 2017 Traverse that came into my shop on a tow truck. The owner was at his wit’s end. It would start fine for a week, then suddenly refuse to crank for a day. Two other shops had replaced the battery and starter to no avail. After hooking up my diagnostic scanner, I saw intermittent communication loss codes (U0100) with the ECM. On a hunch, I gently wiggled the main ECM harness and the engine immediately stalled. The internal board of the original ECM had developed a micro-fracture, causing a connection to fail only when it heated up. Replacing it with a pre-programmed 2017 Enclave ECM (same family) solved the problem instantly. It’s a classic example of how ECM failure can mimic other issues.