Volkswagen New Beetle. Manual - part 1455

 

  Index      Volkswagen     Volkswagen New Beetle 1998-2008 year - service repair manual

 

Search            

 

 

 

 

 

 

 

 

 

Content   ..  1453  1454  1455  1456   ..

 

 

Volkswagen New Beetle. Manual - part 1455

 

 

In limited quantities, fuel vapors located at the highest point in the tank pass through a gravity valve (which 
closes at an angle of 45°) and through a pressure retention valve into the EVAP canister. 

The activated charcoal in the canister stores these vapors like a sponge. 

When the oxygen sensor control is active when driving (engine warm), the EVAP canister purge regulator valve 
-N80- is activated (pulsed) from the engine control module depending upon load and engine speed. The opening 
period is dependent on the input signals. 

Intake manifold vacuum draws fresh air through the vent opening on the underside of the EVAP canister during 
the purging procedure (regenerating the activated charcoal). The fuel vapors stored in the activated charcoal and 
fresh air are fed for combustion in dosed quantities. 

The pressure retention valve prevents fuel vapors from being drawn from the tank when the solenoid valve is 
open and an intake manifold vacuum is present. It therefore ensures that the evacuation of the EVAP canister 
has priority. 

When no voltage is applied (e.g. wiring open circuit), the solenoid valve is closed. The EVAP canister will not 
be purged. 

The vacuum line from the throttle valve control module to the EVAP canister has an additional bypass which is 
connected with the crankcase breather valve. The non-return valve integrated in the crankcase breather valve 
prevents the intake air gassing into the crankcase during some partial load ranges. This improves the overall 
crankcase breathing. The bypass guarantees the crankcase breathing. 

Functional description of leak diagnosis 

The EVAP system (including the fuel tank) is equipped with a leak diagnosis. This diagnosis system detects 
leaks in breather system. 

This diagnosis is based on the pressure principle and should detect leaks with a circumference larger than 1 mm.

During the diagnosis the Leak Detection Pump (LDP) -V144- creates a pressure of 30 mbar in the EVAP 
system. When the pressure is attained the pump switches off. If the pressure drops below a predetermined value 
the pump switches on again. The self-diagnosis monitors the switching periods and sets a fault in the fault 
memory when the period is too short. 

Observe safety precautions. See SAFETY PRECAUTIONS WHEN WORKING ON THE FUEL SUPPLY 
SYSTEM
 . 

Observe rules for cleanliness. See RULES FOR CLEANLINESS . 

EVAP system components, servicing. See EVAP SYSTEM COMPONENTS, SERVICING . 

EVAP system, assembly overview. See EVAPORATIVE EMISSIONS (EVAP) SYSTEM, ASSEMBLY 
OVERVIEW
 . 

 

2003 Volkswagen New Beetle GLS 

1998-2004 ENGINE Fuel Supply - 2.0L (AEG, AVH, AZG, BDC, BEV & BGD)

  

EVAP SYSTEM COMPONENTS, SERVICING 

1. Leak Detection Pump (LDP) -V144-*/** 

z

In right rear wheel housing, behind wheel housing liner  

2. Connector 

z

Black, 3-pin  

3. Vacuum line 

z

To intake manifold upper part. See Fig. 49 , item -6-. 

NOTE:

z

Hose connections are secured with either spring-type or clamp-type clips. 

z

Always replace clamp-type clips with spring-type clips.  

z

Always replace clamp-type clips with spring-type clips. Assembly tool 
VAS 5024 or hose clip pliers V.A.G 1921 are recommended for installing 
spring-type clips. 

Fig. 46: Identifying Special Tool 
Courtesy of VOLKSWAGEN OF AMERICA, INC. 

NOTE:

The following list refers to items in Fig. 47 . 

z

Components marked with an * are checked by the self-diagnosis. 

See Diagnostic tester VAS 5051; Vehicle self-diagnosis 

z

Components marked with ** are checked by the final control diagnosis. 

See Diagnostic tester VAS 5051; Vehicle self-diagnosis 

NOTE:

The following list refers to items in Fig. 47 .

 

2003 Volkswagen New Beetle GLS 

1998-2004 ENGINE Fuel Supply - 2.0L (AEG, AVH, AZG, BDC, BEV & BGD)

  

z

Press together at front to release  

4. Breather pipe 

z

Black  

z

Check if seated securely  

z

From changeover valve on fuel tank. See ENGINE CODES BEV, BGD , item -14-  

z

Press together at front to release  

5. To EVAP canister purge regulator valve -N80- 

z

White  

z

Check if seated securely  

z

To EVAP canister purge regulator valve -N80-.  

6. EVAP canister 

z

In right rear wheel housing, behind wheel housing liner  

z

To remove and install, remove turn signals  

7. 10 N.m  

8. 2 N.m  

9. Air filter for leak detection pump  

10. Connecting hose 

z

Suction side  

11. Connecting hose 

z

Pressure side  

Fig. 47: Exploded View Of EVAP System Components 
Courtesy of VOLKSWAGEN OF AMERICA, INC.

 

2003 Volkswagen New Beetle GLS 

1998-2004 ENGINE Fuel Supply - 2.0L (AEG, AVH, AZG, BDC, BEV & BGD)

  

EVAPORATIVE EMISSIONS (EVAP) SYSTEM, ASSEMBLY OVERVIEW 

Engine codes AEG, AVH, AZG 

z

Engine code BDC. See ENGINE CODE BDC  

z

Engine codes BEV, BGD. See ENGINE CODES BEV, BGD  

1. Tank flap unit 

z

With rubber cup  

2. Fuel tank 

z

When removing, support with engine/transmission jack V.A.G 1383 A 

z

Removing and installing. See FUEL TANK, REMOVING AND INSTALLING  

3. Fuel delivery unit 

z

Removing and installing. See FUEL DELIVERY UNIT, REMOVING AND INSTALLING  

4. Throttle valve control module -J338-  

5. Intake manifold upper part  

6. Fuel rail with injectors  

7. Fuel pressure regulator  

8. Fuel filter 

z

Installed position: Arrow points in direction of flow  

9. EVAP canister purge regulator valve -N80- 

z

On right in engine compartment above wheel housing liner  

z

Installed position: Arrow points in direction of flow  

z

Valve will be activated by engine control module (pulsed)  

10. Test union  

11. Gravity valve  

12. Pressure retention valve 

z

For fuel tank breather  

z

Checking. See Checking Pressure Retention Valve  

13. Change-over valve 

z

Check. See Checking Change-Over Valve  

14. EVAP canister 

z

In right rear wheel housing, behind wheel housing liner  

15. Leak Detection Pump (LDP) -V144- 

z

At EVAP canister  

z

Pump will be activated by engine control module (pulsed)  

16. Air filter for LDP  

NOTE:

The following list refers to items in Fig. 48 .

 

2003 Volkswagen New Beetle GLS 

1998-2004 ENGINE Fuel Supply - 2.0L (AEG, AVH, AZG, BDC, BEV & BGD)

  

 

 

 

 

 

 

 

Content   ..  1453  1454  1455  1456   ..