System Description

WARNING: This page is about a different car, the 2006 Suzuki Reno and 2006 Suzuki Forenza. However, it is still accessible from the selected car via links, so may be relevant.

The Evaporative (EVAP) emission system includes the following components:

Fuel tank
EVAP emission vent solenoid
Fuel tank pressure sensor
Fuel pipes and hoses
Fuel vapor lines
Fuel cap
EVAP emission canister
Purge lines
EVAP emission canister purge valve
EVAP emission service port

The EVAP emission system is checked by applying vacuum to the EVAP emission system and monitoring for a vacuum decay. The Engine Control Module (ECM) monitors the vacuum level through the fuel tank pressure sensor signal.

At the appropriate time, the EVAP canister purge valve and the EVAP vent solenoid are turned ON, allowing the engine to draw a small vacuum on the entire evaporative emission system. After the desired vacuum level has been achieved, the EVAP canister purge valve is turned OFF, sealing the system. A leak is detected by monitoring for a decrease in the vacuum level over a given time period, when all other variables remain constant. A small leak in the system will cause Diagnostic Trouble Code (DTC) P0456 to be set.