Check DTC Memory (Function 02)

Check DTC Memory - Function 02

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.). This information especially facilitates determining sporadically occurring malfunctions. 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.
- On vehicles equipped with rear A/C system, the DTC "Check DTC memory of Climatronic Control Module" is entered in Rear A/C Control Head (Climatronic) E265 for certain malfunctions at the front A/C system. Therefore, also check DTC memory of Rear A/C Control Head (Climatronic) E265 on these vehicles after erasing DTC memory of front Climatronic Control Module J255.

- With ignition switched off, connect e.g. Vehicle Diagnosis, Testing and Information System VAS5051/5052 with Diagnostic Cable - 3 Meter VAS5051/5A to the vehicle 16- pin Data Link Connector (DLC), switch ignition on and select address word "08" the front Climatronic Control Module J255 or address word "28" the Rear A/C Control Head Climatronic) E265. Vehicle Diagnostic, Testing and Information System VAS5051/5052, Connecting and Selecting Functions
- Select "02 - Check DTC memory" function.
- In one display field, e.g. the number of stored DTCs is displayed.
- In another display field, e.g. the DTC, the malfunction location and malfunction type of the saved malfunction are displayed.

NOTE:
- By clicking the <- button, you will return to the selection menu.
- By pressing the respective button (e.g. -> button), general and ambient conditions under which the malfunction(s) occurred can be displayed.
- 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.

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 measuring value block (function 08).
2. Perform output Diagnostic Test Mode (DTM) (function 03).
3. 3.Check coding of front A/C control head Climatronic Control Module J255 (function "07").
4. 4.Check adaptation of front Climatronic Control Module J255 (and Rear A/C Control Head (Climatronic) E265) (function "10").
5. 5.Check cooling/heating performance of A/C system.

If one or more malfunctions were recognized:
1. Repair malfunction.
2. Check DTC memory of front Climatronic Control Module J255 (and Rear A/C Control Head (Climatronic) E265) (function 02).
3. Erase DTC memory (function 05)
4. Check coding of front A/C control head Climatronic Control Module J255 (function "07").
5. Check DTC memory of front Climatronic Control Module J255 (and Rear A/C Control Head (Climatronic) E265) (function 02).
6. Check adaptation of front Climatronic Control Module J255 (and Rear A/C Control Head (Climatronic) E265) (function "10").
7. Check DTC memory of front Climatronic Control Module J255 (and of Rear A/C Control Head (Climatronic) E265) (function "02") and if necessary repair malfunctions displayed, erase DTC memory (function "05") and repeat procedure once more.
8. End Output (function "06").

Indication on display of Vehicle Diagnosis, Testing and Information System VAS5051/5052 :
- End Output (function "06"). Erase DTC Memory (Function 05), End Output (Function 06)
- Switch off ignition and disconnect diagnostic cable.