Selectable functions (modes) under address word 33, CARB / OBD II
| Function | Prerequisite | |||
| Functions on VAG1551 scan tool or on VAG1552 vehicle system tester | Engine stopped, ignition switched on | Engine running at idling speed | Vehicle being driven | |
| Mode 1 | Transfer diagnostic data | yes | yes | yes |
| Mode 2 | Transfer operating conditions | yes | yes | yes |
| Mode 3 | Check DTC Memory | yes | yes | yes |
| Mode 4 | Erase DTC Memory (diagnostic data) | yes | yes | yes |
NOTE:
- The individual read values can be read in mode 1. Mode 1 is not recommended for the VW specialist workshops, because this data is more comprehensively available under address word 01/function 04 or function 08.
- Mode 2 shows the operating conditions under which a malfunction was detected.
- The DTC memory is interrogated with mode 3 and the DTC memory (diagnostic data) erased with mode 4.
| Function | Prerequisite | |||
| Functions on VAG1551 scan tool or on VAG1552 vehicle system tester | Engine stopped, ignition switched on | Engine running at idling speed | Vehicle being driven | |
| Mode 5 | Oxygen sensor signal output | yes | yes | yes |
| Mode 6 | Transfer measured values | yes | yes | yes |
| Mode 7 | Check DTC Memory | yes | yes | yes |
| Mode 8 | Tank system check | no | yes | no |
NOTE:
- Mode 5 displays the statistical levels for the oxygen sensors required by legislation. As these levels do not have any direct reference to the oxygen sensors diagnostic, mode 5 is irrelevant for the VW specialist workshop.
- In mode 6 the measured values of components and systems which are not continually being monitored can be checked.
- In mode 7 codes can be checked which have not caused the Malfunction Indicator Light (MIL) to switch on (MIL is not on, no malfunction in mode 3).
- In mode 8 leaks in fuel tank system can be detected. evaporative emission (EVAP) canister purge regulator valve N80 and fuel system Leak detection pump (LDP) V144 seals the fuel tank system. A pressure (max. 70 mbar) can be created in fuel tank system via test connection (on right in engine compartment) and leaks can be determined with aid of engine leak detection spray G 001 800 A1.