Functional test
WARNING: This page is about a different variant/trim than selected.
- Connect Scan tool VAG 1551 (or system tester VAG 1552 ). Leave engine running and select engine control module using "address word" "01". Refer to 01 ON BOARD DIAGNOSTIC (OBD)
Indicated on display:
| Rapid Data Transfer HELP Select Function XX |
- Press keys "0" and "8" for function "Read Measuring Value Block" and acknowledge entry by pressing "Q."
Indicated on display:
| Read Measuring Value Block Enter Display Group No. XXX |
- Press keys "0" , "7" and "1" for display group 71 and acknowledge entry by pressing "Q."
Indicated on display
| Read Measuring Value Block 71 -> Reed closed Abort Test OFF |
or
Indicated on display
| Read Measuring Value Block 71 -> Reed closed Messg.END Syst. OK |
- Check display in field 1:
| Display Fields | ||||
| 1 | 2 | 3 | 4 | |
| Display Group 71: Diagnosis of evaporative emissions system (leak testing) | ||||
| Display | Reed open Reed closed | Fine leak/large leak Stop | Syst. Test measurement end of measurement | test OFF/test ON Syst. OK Syst. nOK |
| Indicator | Reed-contact status | Error message | System status | status of diagnosis and result |
| Working range | --- | --- | --- | --- |
| Specification | Reed closed | --- | END of measurement | System OK |
If "reed open" appears in field 1:
- Briefly open fuel tank cap to reduce tank pressure. This will close reed contact.
If the specification is attained:
- Press "4" for function "start basic setting."
Indicated on display (1-4 = display fields).
| System in basic setting 71 -> 1 2 3 4 |
- Let engine idle until "Syst. nOK" is displayed in field 4.
If "reed open" appears in field 1:
- Briefly open fuel tank cap to reduce tank pressure. This will close reed contact.
If diagnosis is started by engine control module, display in field 4 will jump from "Test OFF" to "Test ON".
| Display fields | ||||
| 1 | 2 | 3 | 4 | |
| Display Group 71: Diagnosis of evaporative emissions system (leak testing) | ||||
| Display | Reed open Reed closed | Syst. Test Measurement End of measurement | Test OFF/test ON Syst. OK Syst. nOK | |
| Indicator | Status of reed contact | System status | Status of diagnosis and Result | |
| Working range | --- | --- | --- | |
| Specifications | Reed closed | END of measurement | System. OK | |
NOTE:
- If field 4 switches from "Test ON" to "Test OFF" during the diagnosis, repeat the leak testing.
- The fuel tank cap must be opened briefly before the diagnosis can be repeated.
If the indicator does not behave as described:
If the specifications were attained:
- Press, → button.
- Press keys "0" and "6" for function "end output" and acknowledge with "Q."
- Turn off ignition.
If the specifications were not attained:
- Press "8" for function "Read Measuring Value Block".
Indicated on display
| Read Measuring Value Block 71 -> Reed open Messg. END Syst. OK |
- Press "1" for display group 70 and acknowledge with "Q."
Indicated on display (1-4 = display fields)
| Read Measuring Value Block 70 -> 1 2 3 4 |
- Press "4" for function "basic setting." Leak test is started.
NOTE:
- No load may be produced during this diagnosis. Otherwise the diagnosis will be stopped and can only be started again after applying the accelerator.
Indicated on display (1-4 = display fields)
| System in Default70 -> 1 2 3 4 |
If diagnosis is started by ending control module, display in field 4 will jump from "Test OFF" to "Test ON".
- Let engine idle until specification "TEV OK" is displayed in field 4.
NOTE:
- If the display jumps from "Test ON" to "Test OFF" during the test, the test can be repeated by a short application of the accelerator.
| Display Fields | ||||
| 1 | 2 | 3 | 4 | |
| Display Group 70: Diagnosis of evaporative emissions system (leak testing) | ||||
| Display | xxx % | xx.x % | xx.x g/s | Test OFF/test ON TEV OK TEV nOK |
| Indicator | Solenoid valve opens during diagnosis | Deviation of A/F control during diagnosis | Idle deviation during diagnosis | status of diagnosis and result |
| Working Range | 0-100 % | -25.0-25.0 % | -2.7-2.8 g/s | --- |
| Specification | --- | --- | --- | TEV OK |
If "TEV nOK" is displayed in field 4:
- Start output DTM and trigger Evaporative emission (EVAP) canister purge regulator valve N80 : Refer to 01 ON BOARD DIAGNOSTIC (OBD)
- Read readiness code: Refer to 01 ON BOARD DIAGNOSTIC (OBD)
- If DTC memory has been erased or engine control module was separated from positive voltage supply, readiness code must be regenerated: Refer to 01 ON BOARD DIAGNOSTIC (OBD)
If the specification "TEV OK" was achieved:
- Press, → button.
- Press keys "0" and "6" for function "end output" and acknowledge entry with "Q."
- Turn off ignition.