Foothills Group Lethbridge

🔧 Duramax 6.6 Diagnostic Training
This truck came in hunting, surging, and struggling to idle.
The fault codes pointed us toward the MAF circuit, but instead of throwing parts at it, we started testing. Along the way, we found a temporary solution that helped the truck idle properly while we continued tracking down the real issue.
A good reminder that a fault code tells you where to look — not what to replace.

Why disconnecting the MAF is a short term fix! Sure it can run but it will for sure have problems, it did get us running to keep troubleshooting.

Customer complaint:
“The truck feels like it’s steering itself down the road.” 😭
Turns out excessive play in the steering gear travels all the way through the drag link and steering arm… letting the wheels shimmy around even while the steering wheel looks straight 🔧
Tiny steering slop = major highway anxiety.

Started with a parking brake issue…
ended with our mechanic digging through mud, tape, and a destroyed harness just to find ONE broken wire 😭🔧
Sometimes the whole machine acts possessed because of something smaller than your pinky finger.