Malfunction Recognition

Malfunction Recognition

Malfunctions occurring in monitored sensors and components are stored in the DTC memory together with the malfunction type.

The first step in the troubleshooting process is always to start On Board Diagnostic (OBD) and check the DTC memory. This can be performed with the following:

- Diagnostic Operation System VAS 5051 A
- Vehicle Diagnosis Service Syst. VAS 5052
- Fault Read Out Device V.A.G 1551
- Mobile Scan Tool V.A.G 1552

The stored DTC displayed can be compared with a DTC table (containing information on possible causes of trouble) to perform specific repair procedures.

NOTE:
- If a malfunction exists for longer than a certain period, the malfunction is stored as being static. If the malfunction situation is then no longer detected for a predetermined period, the malfunction is reclassified as being sporadic. This process is constantly repeated. Sporadic malfunctions are additionally identified as such by/SP on the display.
- A sporadic malfunction is erased automatically if it no longer occurs for a predetermined period.

The On Board Diagnostic (OBD) options can only be performed with the Diagnostic Operation System VAS 5051 A, the Vehicle Diagnosis Service Syst. VAS 5052, the Fault Read Out Device V.A.G 1551 or the Mobile Scan Tool V.A.G 1552 in mode "1" (Rapid data transfer).

On Board Diagnostic (OBD) is not restricted to storage, checking, erasing and Output Diagnostic Test Mode (DTM) diagnosis. It also has basic setting, control module identification, adaptation and coding functions.

Mode "2" (blink code output) is not available for the A/C heater electronics. Modes "3" (self-test) and "4" only apply to the Fault Read Out Device V.A.G 1551 and the Mobile Scan Tool V.A.G 1552 and are described in the relevant operating manuals.

Available functions







NOTE:
- On Board Diagnostic (OBD) can be performed using the Vehicle Diagnosis Service Syst. VAS 5052, the Fault Read Out Device V.A.G 1551 or the Mobile Scan Tool V.A.G 1552. In order to have a record of any faults, it is appropriate to connect the Diagnostic Operation System VAS 5051 A or the Fault Read Out Device V.A. G 1551 before erasing the DTC memory and to print out the faults present (the Mobile Scan Tool V.A. G 1552 is not equipped with a printer).
- If a new operating and display module, Climatronic Control Module J255 has been installed and Basic Setting was not performed after installation, the A/C Compressor Regulator Valve N280 is not activated and display group "002" in the measuring value block indicates compressor shutoff condition "6".
- A/C control is not interrupted when starting On Board Diagnostic (OBD). It is however deactivated on selecting the following functions: "Output Diagnostic Test Mode (DTM) diagnosis", "Basic setting procedure".
- Control function remains fully operational when other functions are selected.
- For install locations of air conditioner components.