With Manufacturer Scan Tool
Diagnostic Trouble Code (DTC) Memory, Checking (Function 02)
- Connect VAG 1551 Scan Tool (ST). Scan Tool Connecting and Initial Checks
- Press buttons -0- and -8- to insert "AC/Heating Electronics" address word 08 and advance program until "Select function XX" appears on display. Scan Tool Connecting and Initial Checks
- Switch printer on by pressing PRINT button (indicator lamp in button comes on).
Indicated on display (function selection)
Rapid data transfer HELP
Select function XX
- Press buttons -0- and -2- to select "Check DTC Memory" function 02.
Indicated on display
Rapid data transfer Q
02 - Check DTC Memory
- Press -Q- button to confirm input.
Number of stored DTCs is displayed
Rapid data transfer Q
X DTC recognized
- Press -> button.
If "No DTC recognized" is displayed, the program returns to the starting position after -> button is pressed.
Rapid data transfer Q
No DTC recognized
- Press -> button.
Stored DTCs are displayed and printed sequentially.
When the last DTC has been displayed and printed out, the malfunction must be repaired using DTC table. Heating and Air Conditioning
The program returns to its starting position when the -> button is pressed. (The same applies when the message "No DTC recognized" is displayed.)
Indicated on display
Rapid data transfer HELP
Select function XX
- End output (function 06). End Output (Function 06)
- Switch ignition off and disconnect Data Link Connector (DLC).
If a DTC was recognized:
- Repair malfunction.
- Check DTC memory (function 02).
- Erase DTC memory (function 05).
- Check control module versions (function 01) or code control module (function 07), respectively.
- Perform basic setting (function 04).
- Check DTC memory (function 02) and erase DTC memory (function 05), if necessary.
- End output (function 06).
If no DTCs have been recognized, but the air conditioning is not working properly (e.g. the compressor is not functioning or only functioning for certain periods of time, there is unsatisfactory regulation of the system or the fresh air blower speed cannot be controlled):
- Read measuring value block (function 08). Reading
- Perform output Diagnostic Test Mode (DTM) (function 03). Output Diagnostic Test Mode (DTM) (Function 03)
- Check A/C cooling performance. A/C Cooling Performance, Testing
NOTE:
- If no signal for the "ignition off" period is detected by the A/C Control Head -E87- when the ignition is switched on, -E87- assumes that the vehicle has been left standing for more than 4 hours, and the engine temperature is assumed to be identical to the ambient temperature. If the system is in heating mode, there may be a delay before the fresh air blower switches on, even though the engine is warm. The outside air temperature display -G106- in the instrument cluster may also display incorrect ambient temperature values. Read Measuring Value Blocks (Function 08)
- If the illumination of the A/C Control Head -E87- does not light up when the ignition is switched on, restore the voltage supply to -E87- from terminals 88, 58d and 58s (dimming). Read Measuring Value Blocks (Function 08) Component Tests and General Diagnostics