With Manufacturer's Scan Tool

Evaporative Emissions (EVAP) System Diagnostic Leak Test, Performing

Special Tools and Equipment







- VAS 5051 with VAG 5051/1


NOTE:
- Secure all hose connections using hose clamps appropriate for the model type.
- Always replace seals and gaskets.

Test requirements
- Parking brake is engaged.
- Vehicles with manual transmission: Shift lever in idle position.
- Vehicles with automatic transmission Selector lever in P or N.
- Engine running at idle:
- Electrical consumers switched off (radiator fan must NOT run during test).







- A/C switched off.
- VAS 5051 tester connected and OBD -01 Engine electronics- selected.
- No DTCs in DTC memory.
- Intake Air Temperature (IAT) less than 90 degrees C, see display group 004, display field 4
- Refrigerant temperature less than 95 degrees C, see display group 004, display field 3
- Throttle valve angle less than 10 degrees % display group 003, display field 3

Test sequence

Display on VAS 5051:







- In selection -1-, click on the diagnostic function "04 - Basic setting".

Display on VAS 5051:







1 - Enter display group
- Select function "071" in button field -2- for "display group number 071" and press Q button to confirm input.

Display on VAS 5051:







- Check indication in display field 1.
- Specification: "Reed closed"


NOTE:
- If "Reed cl" (closed) is displayed, continue test.
- If display indicates "Reed open": briefly open and close fuel filler cap to release pressure from fuel tank. This will close the reed contact.


- Activate basic setting by pressing button A.
- Check indication in display field 4.
- Specification: "Test ON"

The system test lasts several minutes.
- Check indication in display field 4.
- Specification: "System OK"

System is sealed, test is terminated.
- End function "04 - Basic setting" by pressing <- button.

DTC display
If a DTC is recognized during the system test, the DTC evaluation follows.







On VAS 5051 display in display field -4-:
- In case of malfunction: System not OK

- Check diagnosis evaluation in display field -2-.
- "Small leak" or "large leak"

- End function "04 - Basic setting" by pressing <- button.

If the system recognizes a small or large leak:
- Checking fuel supply and ventilation systems for leaks.
- After that, repeat leak test.