Who is correct regarding the type of EVAP system discussed?

• A. Technician A
• B. Technician C
• C. Technician B
• D. Technician D

Answer: (C)

EVAP systems are designed to keep fuel vapors under control by keeping them in a closed loop rather than venting to the atmosphere. In a typical modern setup, vapors from the fuel tank are captured by a charcoal canister. The purge valve, under PCM control, allows those vapors to be drawn into the engine to be burned when conditions are right. A vent valve helps seal the system from the atmosphere during diagnostic checks and normal operation. The PCM monitors the canister’s pressure and valve operation to detect leaks or faults.

Technician C is correct because their description aligns with this sealed, charcoal-canister configuration with purge and vent control. This matches how the system operates during testing and diagnosis, including how vapors are stored and then purged for combustion. The other technicians’ descriptions would imply alternative arrangements—such as a vent-to-atmosphere or a different valve configuration—that don’t fit the typical modern EVAP system and wouldn’t explain the expected diagnostic signals and test procedures.