Check DTC Memory (Function 02)

Checking DTC Memory

NOTE:
- This Repair Information only outlines the function "Check DTC memory". Check DTC memory via "Guided Fault Finding" function, here is also found corresponding notes for determining malfunction location and malfunction repair. Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.
- In addition to DTC display, certain general and ambient conditions under which the malfunction occurred are stored in the control module (e.g. odometer reading, time, date, engine temperature, battery voltage, engine RPM etc.). These items of information are particularly useful for establishing sporadic faults. Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.
- DTC table for malfunction locations and DTC types designated for the A/C system can be found in Guided Fault Finding Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.

- With the ignition switched off, connect the Diagnostic Operation System VAS 5051 A with diagnostic cable VAS 5051/5A to 16-pin Data Link Connector (DLC) in the vehicle and select address word "08" or "28" A/C / Heating Electronics, or "rear A/C control head".







Indication on display of diagnostic operation system VAS 5051 A:
- Select "02 - Check DTC memory" function.







Indication on display of diagnostic operation system VAS 5051 A:
- Display field - 1 - indicates the number of stored malfunctions.
- Display field - 2 - indicates the DTC, the malfunction location and malfunction type of the saved DTC.

NOTE:
- By clicking the <- button, you will return to the selection menu.
- By pressing the -> button, general and ambient conditions under which the malfunction(s) occurred can be displayed.
- If no malfunction is recognized but the climate control system does not operate properly (e.g. always or intermittently no cooling performance, control of system insufficient, fresh air blower speed cannot be regulated), proceed as follows:
1. Read measured value block (function 08).
2. Perform final control diagnosis (function 03).
3. Check coding of Climatronic Control Module J255 (function 07).
4. Check adaptation of Climatronic Control Module J255 (and Rear A/C Control Head (Climatronic) E265) (function 10).
5. Check cooling/heating performance of A/C system, A/C Cooling Output, Checking

If fault(s) are found:
1. Eliminate fault.
2. Interrogate fault memory (function 02).
3. Erase fault memory (function 05).
4. Check coding of Climatronic Control Module J255 (function 07).
5. Perform basic setting (function 04).
6. Check adaptation of Climatronic Control Module J255 (and Rear A/C Control Head (Climatronic) E265) (function 10).
7. Interrogate fault memory (function 02), eliminate faults displayed if necessary, erase fault memory (function 05) and repeat procedure.
8. End output (function 06).
Certain malfunctions can be erased only after starting engine (e.g. "ignition off time period signal" after replacing Instrument Cluster Control Module J285). If a malfunction cannot be erased, start engine and let it run for 1 minute before checking and erasing DTC memory again.

Indication on display of diagnostic operation system VAS 5051 A:
- End output (function 06). End Output (Function 06)
- Switch off ignition and unplug diagnostic connector.