DTC C12C5 GMC
EVAP Control System Large Leak Detected
EVAP Control System Large Leak Detected
Description
Engine started, battery voltage must be at least 11.5v, all electrical components must be off. The coolant temperature is less than 60 degrees Celsius, and the ambient pressure is greater than 76.2994kPa. The air intake temperature at start is between 9.04 and 16.04 degrees Celsius. The change in barometric pressure since engine start is less than 0.9998kPa. The vehicle speed is less than 74.56mph, and the purge valve has opened enough on previous driving cycle. The DME detected multiple small fuel vapor leaks; or it detected a large leak in the system during the leak test.
Cause and Solution
Aftermarket EVAP hardware non-conforming to specifications EVAP canister tube, EVAP canister purge outlet tube or EVAP return tube disconnected or cracked, or canister is damaged EVAP canister purge valve stuck closed, or canister damaged Fuel filler cap missing, loose (not tightened) or the wrong part Loose fuel vapor hose tube connections to EVAP components Canister vent (CV) solenoid stuck open Fuel tank pressure (FTP) sensor has failed mechanically
Video Guide
Diagnostic Info
- DTC Code: C12C5
- Brand: GMC