Evaporative Emissions - V8 S/C 5.0L Petrol (G2796668): Overview

WARNING: This page is about a different variant/trim than selected.

The evaporative emission system reduces the level of hydrocarbons released into the atmosphere by fuel vapor venting from the fuel tank.

Fuel vapor is generated by the fuel in the fuel tank. The amount of fuel vapor produced increases as the fuel temperature rises. Another source of fuel vapor generation is the refueling process. Fuel vapor can flow without restriction to the evaporative emission canister through the tank venting system.

To prevent the charcoal becoming saturated, the fuel vapor is purged from the evaporative emission canister when the engine is running under certain operating conditions. The Powertrain Control Module (PCM) operates the purge valve at the correct times. This allows fuel vapor to be drawn from the evaporative emission canister and burnt in the engine.

The evaporative emission system comprises:

An evaporative emission canister.
An evaporative emission canister air filter.
A purge valve.
Fuel vapor pipe.
Purge line.
A Diagnostic Module Tank Leakage (DMTL) pump (if equipped).
A DMTL filter (if equipped).
A vapor space within fuel tank.
A fuel filler.
A filler cap.

On North American Specification (NAS) market vehicles, there is an additional DMTL system. The DMTL system allows the fuel vapor system to be pressurized and therefore allows detection of a leak.