On-Board Refueling Vapor Recovery Function
On-Board Refueling Vapor Recovery Function
MODEL 170 as of 1.9.00 with ENGINE 111, 112 (except , 112.96) with CODE (494a) USA version
MODEL 202 with ENGINE 111, 112
with CODE (494a) USA version
with CODE (808) Model year 1998
with CODE (809) Model year 1999
with CODE (800) Model year 2000
MODEL 203 with ENGINE 111, 112 (except, 112.96) with CODE (494a) USA version
MODEL 208 with ENGINE 111, 112, 113
with CODE (494a) USA version
with CODE (808) Model year 1998
with CODE (809) Model year 1999
with CODE (800) Model year 2000
with CODE (801) Model year 2001
with CODE (802) Model year 2002
MODEL 209 with ENGINE 112 ,113 with CODE (494a) USA version
MODEL 210.0 as of 1.6.01 with ENGINE 112, 113 with CODE (494a) USA version
MODEL 211 with ENGINE 112, 113 (except, 113.99) with CODE (494a) USA version
MODEL 215 as of 1.9.00 with ENGINE 113, 137, 275 (except 113.99) with CODE (494a) USA version
MODEL 220 as of 1.9.00 with ENGINE 112, 113, 137 (except 113.99) with CODE (494a) USA version
MODEL 230 with ENGINE 112, 113 (except, 113.99) with CODE (494a) USA version
Vehicles with low mounted fuel tank
Model 202, 203, 208, 209, 211
Shown on model 202
45 Filler neck (functions through its shape as a suction jet pump)
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 Air line from expansion reservoir to activated charcoal canister
d to engine
Vehicles with fuel tank in luggage compartment
Model 170, 210.0, 215, 220, 230, 240
45 Filler neck (functions through its shape as a suction jet pump)
45/1 Check valve
45/2 Float with flap
75 Fuel tank
75/1 Safety valve (rollover valve)
77 Activated charcoal canister
77/1 Pressure relief valve (opening pressure approx. 30 to 40 mbar)
Y58/1 Purge control valve
Y58/4 Activated charcoal canister shutoff valve
A Nozzle
a ORVR vent line
b Air intake around the nozzle
c Depressurization in open air (if pressure relief valve 77/1 is open)
d to engine
Vehicles with fuel tank in luggage compartment
Illustrated location on model 230
45 Filler neck
45/2 Float with flap
55/1 Fuel filter with integrated diaphragm pressure regulator
75 Fuel tank
75/1 Safety valve (rollover valve)
75/2 Ventilation pipe of ORVR
77 Activated charcoal canister
B4 Fuel gage sensor
B4/3 Fuel tank pressure sensor
M3 Fuel pump (FP)
Y58/4 Activated charcoal canister shutoff valve
a ORVR vent line
b to purge control valve
c Fuel line to engine
The legislator demands:
- Refueling gases in the vehicle must be collected (ORVR = Onboard Refueling Vapor Recovery).
- Fuel and refueling gases must be separated in order to prevent fuel from flowing into the activated charcoal canister due to inappropriate refueling or a defective nozzle.
The filler neck (45) is designed as a suction jet pump.
The fuel out of the nozzle accelerates through this in the filler neck and air is suctioned around the nozzle.
As a result of this air intake around the nozzle, the refueling vapors are not able to rise up at the filler neck and escape to atmosphere.
The refueling gases are stored in the activated charcoal canister (77) and when releasing regeneration together with fuel gases out of the fuel evaporation control system, are suctioned off and burnt by engine.
If fuel flows to the high mounted safety valves (75/1), they close the vent line to the activated charcoal canister. Through powerful braking, accelerating or cornering the valves can also close briefly.
Model 202, 203, 208, 209, 211
The refueling vapors flow along the vent line (91/2) to the expansion reservoir and on from there to the activatetd charcoal canister.
Model 170, 210.0, 215, 220, 230, 240
In the fuel tank (75), two safety valves (rollover valves) are mounted.
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. A check valve (45/1) prevents the quick increase of fuel in the filler neck. If an excessively high pressure exists in the activated charcoal canister, the pressure relief valve (77/1) opens. In this special case the removal of pressure is performed via the activated charcoal canister shutoff valve (Y58/4) into the open air.
Note: Ending refueling when the refueling nozzle switches off (and the fuel tank is full)! On no account overfilling fuel tank as a result of refueling nozzle being switched on several times.