Checking and Erasing DTC Memory
NOTE:- DTC memory must be checked before it can be erased.
- The main program for the A/C control head -E87- is switched off, and climate control is not operational, during the On Board Diagnostic sequence (i.e. the A/C compressor radiator coolant fan, etc., are not controlled).
Test Conditions:
- Verify that all fuses are OK according to wiring diagram.
Checking:
- Start engine.
- Press "Auto" button on A/C control head.
- Drive vehicle a few yards at walking speed.
- Remove cover from auxiliary relay panel 1 in plenum.
- Connect VAG1551 Scan Tool (ST) and VAG1551/1 adapter to Data Link Connectors (DLC) as follows:
- Connect black connector to black DLC:
- Terminal 1 to Ground (GND)
- Terminal 2 to battery positive voltage (B+) supply
- Connect white connector to white DLC.
- Blue connector is not used.
Operating modes 1 and 2 are displayed alternately
V.A.G. - ON BOARD DIAGNOSTIC HELP
1 - Rapid data transfer C HELP
2 - Blink code output
- If there is no display, check power supply to black DLC. Data Link Connector (DLC) Wiring, Checking
- Press the "HELP" button for additional information.
- Press the -> button to advance the OBD program sequence.
- Press the "PRINT" button to switch on the scan tool printer (indicator lamp in button comes on).
- Press "PRINT" button to switch printer on (indicator lamp in button comes on).
- Press -1- button to select "Rapid data transfer" operating mode 1.
Indicated on display:
Rapid data transfer HELP
Insert address word XX
Press buttons -0- and -8- to insert "AC/Heating Electronics" address word 08, and press -Q- button to confirm input.
Indicated on display (A/C control head identification, coding):
8A0 820 043 Klima-Vollautomat DXX ->
Coding 062 WSC 23890
NOTE: "DXX" indicates the A/C control head -E87- software version (e.g. D01) and has no meaning for OBD.
A/C control head coding description
1st and 2nd digits (where applicable)
00_ _ _ Not used
3rd digit
Code Description
_ _0_ _ Not used
4th digit
Code Engine application
_ _ _6_ 6-cylinder
5th digit
Code Market version Engine type
_ _ __2 USA/Canada Gasoline
NOTE:
- A/C control head coding may be displayed with or without the 1st and 2nd digits (e.g. 062 instead of 00062), depending on the VAG1551 scan tool program card version.
- A/C control head coding procedure.
- Check A/C control head applications.
If one of the following messages is displayed:
Rapid data transfer HELP
Control module does not answer
or
Rapid data transfer HELP
K wire not switching to Ground
or
Rapid data transfer HELP
K wire not switching to B+
or
Rapid data transfer HELP
Error in communication link
- Press "HELP" button to print out list of possible causes.
- Check wire connections of DLC. Data Link Connector (DLC) Wiring, Checking
After repairing possible malfunctions:
- Press -> button.
- Press -0- and -8- buttons to insert "AC/Heating Electronics" address word 08.
- Press -Q- button to confirm input.
- Press -> button.
Indicated on display:
Rapid data transfer HELP
Select function XX
Press buttons -0- and -2- to select the "Check DTC Memory" function 02.
Indicated on display:
Rapid data transfer Q
02 - Check DTC Memory
Press -Q- button to confirm input.
Indicated on display (number of stored DTCs):
X DTC recognized ->
or
No DTC recognized ->
Repair malfunctions as necessary. Automatic Climate Control (Via Scan Tool)
When "No DTC recognized" is displayed Press -> button.
Indicated on display:
Rapid data transfer HELP
Select function XX
If the A/C clutch does not engage, or if the fresh air blower speed cannot be regulated, even though no malfunction was recognized:
- Read measuring value block. Read Measuring Value Block (Function 08)
- Initiate output Diagnostic Test Mode (DTM).
Erasing:
NOTE: If the ignition is switched off, or if engine speed exceeds 4000 RPM between checking DTC memory and erasing, DTC memory will NOT be erased.
Check DTC memory.
Indicated on display:
Rapid data transfer HELP
Select function XX
Press buttons -0- and -5- to select "Erase DTC Memory" function 05.
Indicated on display:
Rapid data transfer Q
05 - Erase DTC Memory
Press -Q- button to confirm input.
If display appears as shown:
Attention! ->
DTC Memory is not interrogated
Check DTC memory following procedure sequence in exact order.
Indicated on display, if DTC memory is successfully erased:
Rapid data transfer ->
DTC Memory is erased
Press -> button.
Indicated on display:
Rapid data transfer HELP
Select function XX
Check basic settings. Basic Setting (Function 04)