GF47.10-P-3004SM Refueling Vapor Recovery - Function

GF47.10-P-3004SM Refueling Vapor Recovery - Function
- MODEL 203 with ENGINE 113.988
- with CODE (494) USA version up to Model Year 8
- MODEL 209 with ENGINE 113.987
- with CODE (494) USA version
- MODEL 215 with ENGINE 113.986
- with CODE (494) USA version
- MODEL 220 with ENGINE 113.986
- with CODE (494) USA version





Vehicle with deeply located fuel tank (models 203, 209)
45 Filler neck
75 Fuel tank
77 Activated charcoal canister
91/2 Vent line (refueling vapors to expansion reservoir)
92 Purge line
93 Expansion reservoir
93/1 Safety valve (rollover valve)
Y58/1 Purge control valve
Y58/4 Activated charcoal canister shutoff valve
a Vent line from the expansion reservoir to the activated charcoal canister
d Fuel gases to the engine





Vehicles with the fuel tank in the trunk (models 171, 215, 220)
45 Filler neck
45/2 Float with flap
55/1 Fuel filter
75 Fuel tank
75/1 Safety valve (rollover valve)
75/2 ORVR vent line
77 Activated charcoal canister
B4 Fuel level sensor
B4/3 Fuel tank pressure sensor (integrated in the fuel level sensor)
M3 Fuel pump
Y58/4 Activated charcoal canister shutoff valve
a ORVR vent line to the activated charcoal canister
b Fuel gases to the purge control valve
c Fuel line to engine

The US legislature requires that:
- Refueling vapors in the vehicle must be caught (ORVR = Onboard Refueling Vapor Recovery)
- Fuel and refueling vapor must be separated in such a manner that no fuel is able to enter the activated charcoal canister even if refueling is not done correctly or if the nozzle is defective

Owing to its form, the filler neck (45) functions as a suction jet pump.
The fuel from the nozzle accelerates in the filler neck and thus air around the nozzle is sucked in.
The result of this air intake is that refueling vapor are not able to gather at the filler neck and therefore not are able to escape.
The refueling vapor is stored in the activated charcoal canister (77) and is suctioned off and burnt by the engine when regeneration is released together with the fuel vapor from the fuel evaporation control system.

Model 203, 209
The refueling vapor flows to the expansion reservoir (93) through the vent line (91/2) and from there out through the safety valve (rollover valve) (93/1) and further to the activated charcoal canister through the vent line (a).

Except models 171, 215, 220
The refueling vapor flows through the safety valves (rollover valves) (75/1), through the ORVR vent line (a) to the activated charcoal canister.
If the fuel reaches the two high safety valves, the valves close the vent line to the activated charcoal canister. The fuel cannot therefore enter the activated charcoal canister. The safety valves can also close briefly on powerful braking / accelerating or while cornering. If the fuel tank is full, the float with the flap (45/2) closes the filler neck at the bottom. This ensures that the refueling nozzle shuts off more rapidly and overfilling is largely prevented.

The activated charcoal canister has a larger volume for ORVR (around 2.7 to 3.5 liters).