Chevrolet OBD2 Diagnostic Portal
Chevrolet trucks and SUVs are built on durable small-block V8 architectures featuring Active Fuel Management (AFM/DFM) cylinder deactivation. AFM lifter collapses and PCV diaphragm ruptures inside the valve cover on 1.4T/1.5T engines represent the majority of driveability codes.
Primary Engine Families Cataloged
Commonly Diagnosed Vehicle Models
Chevrolet Factory Service Advisories & Field Notes
GM throttle bodies suffer from fretting corrosion on the tin-plated harness connector terminals. GM released an updated pigtail kit with gold-plated terminal pins. Wiggling the throttle harness while checking live TPS voltage confirms the issue.
The factory EVAP vent solenoid mounted near the spare tire draws in road dust and gravel, jamming the valve. GM engineered an updated vent valve kit with a remote breather filter routed up into the truck frame.
The orange silicone check valve inside the intake manifold disintegrates, putting crankcase boost pressure directly against the valve cover PCV diaphragm until it bursts with a high-pitched whistling noise.
High-Frequency Chevrolet Trouble Codes
Click any diagnostic trouble code to view in-depth multimeter specs, factory TSBs, and repair workflows: