On-Board Refueling Vapor Recovery Function - GF47.10-P-3004MMY
ENGINE 157.9, 278.9 in MODEL 166
as of model year 2016
with CODE 494 (US version)
ENGINE 157.9, 278.9 in MODEL 292
with CODE 494 (US version)
Schematic illustration of fuel tank
On-board refueling vapor recovery, general points
The law requires, that the refueling gases in the vehicle are collected (Onboard Refueling Vapor Recovery).
Fuel and refueling vapors must be separated in order to prevent fuel from flowing into the activated charcoal canister due to any inappropriate refueling or a defective nozzle.
Function sequence for on-board refueling vapor recovery
Owing to its form, the filler neck functions as a suction jet pump. The fuel out from nozzle thus accelerates in the filler neck and the air around the nozzle is suctioned into the fuel tank.
As a result of this air intake. The refueling vapor are not able to gather at the filler neck and are able to escape.
The fuel vapors flow through the aeration/vent valves and aeration/vent lines to the activated charcoal canister, where they are stored.
The fueling, pressure limitation and vent valve also prevents overfilling by closing off the aeration and vent line.
Rollover valves are integrated at the top of the aeration/vent valves. If fuel gets into aeration/vent valves, they close off the aeration/vent lines to the activated charcoal canister, thus preventing fuel from flowing into the activated charcoal canister.
The aeration/vent valves can also close briefly if there is sudden braking or acceleration, or when cornering.
When purging is enabled, the fuel vapors are drawn off through the purge line by the engine, and burnt together with the fuel gases from the activated charcoal canister.
| Overview of system components for gasoline injection and ignition system with direct injection | GF07.70-P-9998MNG |