Diagnostic Trouble Code Memory Checking

A 16-pin Data Link Connector (DLC) is used for access to the vehicles On Board Diagnostic (OBD) systems using the VAG 1551 Scan Tool (ST).

REQUIREMENTS
- Battery Positive Voltage (B+) OK.
- Fuse no. 22 (S22) OK.
- Ground (GND) connections for engine and transmission which are located on the upper intake manifold support to lower part of intake manifold, are OK.




CHECKING TROUBLE CODE MEMORY
For access to the Data Link Connector:

- Remove front ashtray.
- Slide small cover to the left (arrow).
- With ignition switched off, connect VAG 1551/3 adapter harness between Data Link Connector and VAG 1551 Scan Tool.

^ Indicated on display:

VAG - ON BOARD DIAGNOSTICS HELP
1 Rapid data transfer
2 Blink Code Output

NOTE:
- Operating modes 1 and 2 are displayed alternately.

- Start engine and let idle.

If engine does not start:
^ Operate the starter for approx. six seconds. Do not switch the ignition off.

- Operate VAG 1551 Scan Tool according to information and instructions on the display.
- Press button -1- for "Rapid data transfer" operating mode.
- Press PRINT button to switch the printer on (indicator lamp in button lights up).
- Press buttons -0- and -1- to enter address word 01 for "Engine Electronics".
- Press -Q- button to confirm input.
- Press --> button.
- Press buttons -0- and -2- to select the "Check DTC Memory" function.
- Press -Q- button to confirm input.
- The number of stored Diagnostic Trouble Codes (DTCs) will be indicated or "No DTC recognized" will be displayed.

^ Indicated on display:

X DTC recognized
No DTC recognized

NOTE: If anything else appears in the display, check the VAG 1551 Scan Tool operating instructions.

- If one or more DTCs are stored, they will be displayed and printed out in sequence.
- If no Diagnostic Trouble Code is recognized:

- Press --> button.

- If one or more DTCs are stored:

- Press buttons -0- and -5- to select the "Erase DTC Memory" function.
- Press -Q- button to confirm input.

^ Indicated on display:

Rapid data transfer -->
DTC Memory is erased

NOTE: If the ignition was switched off between checking and erasing the DTC Memory, the DTC Memory will not be erased.

- Press --> button.

^ Indicated on display:

Rapid data transfer HELP
Select function XX

- When DTC Memory is clear (No DTC recognized or DTC Memory is erased):

- Press buttons -0- and -6- to select the "End output" function.
- Press -Q- button to confirm input.
- In the Diagnostic Trouble Code (DTC) table, look up the Diagnostic Trouble Codes that are printed out, and repair. Testing and Inspection

NOTE: The DTC table lists DTCs in sequence according to the 5-digit code.

- Test-drive car for at least 10 minutes.
- The following requirements should be met while test driving:

^ Coolant temperature must be over 80°C (176°F) for at least 3 minutes.
^ At engine speed over 4600 rpm, briefly press accelerator pedal to the floor.
^ In 4th gear, starting from approx. 50 km/h (30 mph), accelerate for about 4 seconds with accelerator pedal pressed halfway down.

- Check and erase DTC Memory again. Clearing Diagnostic Trouble Codes