EVAP Purge Flow Monitor Failure

Name of Code:
EVAP Purge Flow Monitor Failure

When Monitored:
With engine temperature greater than 170°F, engine in closed loop, engine idling for 2 minutes, no low fuel, MAP less than 15.7 inches mercury, and barometric altitude less than 8,000 feet.

Set Condition:
Note: Vehicles with leak detection pump (LDP) must pass stricter EVAP system test first. No air flow through the evaporative system is detected by the EVAP monitor.

Theory of Operation:
The function of the EVAP control system is to prevent the emissions of gasoline vapors from the fuel tank into the atmosphere. The fuel vapor is temporarily held in the EVAP canister and is recirculated via the EVAP solenoid through the air intake system and consumed during combustion. The evaporative system consists of the fuel tank, vapor flow control orifice, EVAP solenoid, and EVAP canister connected by a series of rubber hoses and plastic connectors.

Possible Causes:
- Rubber hose(s) pierced, cut, cracked, kinked or off (solenoid to throttle body)
- Plastic connector to EVAP solenoid cracked
- EVAP solenoid malfunction
- Hose plugged from solenoid to canister
- Hose plugged from throttle body to solenoid
- Connector terminals
- Connector wires