Automatic EVAP System, Diagnostic Leak Test With VAS 5051

Automatic Evaporative Emission (EVAP) System, Diagnostic Leak Test
If a straight automatic tank leakage diagnosis is completed, refer to diagnosis -, measuring and information system VAS 5051 in the measured value block 071. Testing and Inspection

Diagnostic leak test, performing

NOTE:
- Secure all hose connectors with hose clamps, which correspond to the series conditions.
- Replace sealing rings and seals with assembly

Special tools, testers and auxiliary items
- VAS 5051

Test requirements
- Parking brake applied
- Vehicles with automatic transmission: Gear selector lever in P or N
- Vehicles with manual transmission: Gear lever in neutral
- No DTCs in DTC memory
- Electrical consumers switched off (radiator fan must NOT run during test)







- Vehicle diagnosis -, measuring and information system VAS 5051 attached, vehicle self-diagnosis and vehicle system "01 - engine electronics" selected.
- A/C switched off
- Intake Air Temperature (IAT) less than 90 degree C, see display group 004, display field 4.
- Coolant Temperature less than 95 degree C, see display group 004, display field 3.
- Throttle valve angle less than 10 degrees, see display group 003, display field 3.

Test procedure

VAS 5051:







- Touch selection -1- "04 - basic adjustment".


VAS 5051:







1 - Enter display group
- Type in display group -2- "071" for "display group number 071" and confirm by touching the Q-key.

VAS 5051:







- Check the display in display field -1-.
- Desired value: "Reed closed"

NOTE:
- If "Reed 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 adjustment by touching the A key.
- Check the display in display field -4-.
- Desired value: "Test ON"

The system test may require a minute to complete
- Check the display in display field -4-.
- Desired value: "System OK"

System is sealed; test is terminated.
- Quit function "04 - basic adjustment" by touching the A key.

Error display
During the system test if an error was recognized, the evaluation of the error takes place.

Display on VAS 5051 in display field -4-:







- In the event of an error: Syst.n.i.O.

- Check the results of the diagnosis in display field -2-.
- "Small leak" or
- "large leak"

- Quit function "04 - basic adjustment" by touching A key.

The system recognized a fine or a rough leakage:
- Tank system and tank ventilation system on leakage test. Testing and Inspection
- Repeat the leakage diagnosis test again