Refueling Vapor Recovery System: Description and Operation

GF47.10-P-3004MI On-board Refueling Vapor Recovery Function
- MODEL 204.0 /2 with ENGINE 272.9 (except 272.98) as of Model Year 2009
- with CODE (494) USA version /AEJ 08
- MODEL 204.9, 207.3 /4, 212.0 /2 with ENGINE 272.9 (except 272.98)
- with CODE (494) USA version
- MODEL 207.3 /4, 212.0 /2 with ENGINE 273.9
- with CODE (494) USA version





Schematic representation
1 Activated charcoal canister chamber 1
2 Activated charcoal canister chamber 2
3 Activated charcoal canister chamber 3
45 Fuel filler neck
58 Fluid reservoir
75 Fuel tank
75/1 Fueling, limiting and vent valve
75/2 Breather valve
77 Activated charcoal canister
B4/3 Fuel tank pressure sensor
Y58/1 Purge control valve
Y58/4 Activated charcoal filter shutoff valve
A Air admission line and vent line
B Purge line

On-board refueling vapor recovery, general points
The legislator 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 inappropriate refueling or a defective nozzle.

On-board refueling vapor recovery, function sequence
Thanks to its shape, the fuel filler neck functions as a suction jet pump. The fuel out of the nozzle accelerates through this in the filler neck and 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 fuel 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/limiting/vent valve also prevents overfilling by closing off the aeration/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.