How to Read Diagnostic Trouble Codes (DTC's)

Reading Fault memory, using VAG 1551 Diagnostic Tester

[ VAG Self Diagnosis HELP ]
[ 1 - Rapid data transfer ]

After connecting VAG 1551 diagnostic connector display will alternate and appear as shown:

[ VAG Self Diagnosis HELP ]
[ 2 - Blink code output ]

Note: Press the PRINT button for a complete printout of fault functions.

[ Blink code output ]
[ is being initiated ]

^ select operating mode 2, blink code output

^ press => button and hold, display will appear as shown

[ Blink code output ]
[ Permanent ground on exciter wire ]

after approximately 2.5 seconds display will appear as shown:

^ release => button
^ switch ON ignition
^ ABS indicator (K 47) lights up

[ Blink code XXXX ]
[ ]

^ operate => button briefly, display shows:

If a fault is stored it will appear via the indicator light (blinking) and in the tester display, e.g.:

[ Blink code 1241 ]
[ Speed sensor front right - G 45 ]

^ operate => button briefly to call up next blink code
^ indicator light (K 47) blinks each fault in code, and display appears on screen as shown in example display

[ Blink code 4444 ]
[ No faults recognized! ]

If display appears as shown:
^ switch ignition OFF
^ self-diagnosis is complete

[ Blink code output ]
[ No blink code received! ]

If display appears as shown
^ check wire from terminals 26 and 27 of ABS control unit (J 104) to tester

[ Blink code 0000 ]
[ End of output ]

^ continue fault code call-up until display appears as shown:
and then:

[ Blink code output ]
[ is completed! ]

^ switch ignition OFF
^ see fault table/blink code, and eliminate faults
^ after repairs, switch ignition ON for approximately four seconds

If indicator light (K 47) goes out, ABS is free of faults
^ erase Fault memory

If indicator light (K 47) does not go out
^ read Fault memory again

Note: If more than one fault was displayed, faults which have been eliminated will also be shown again.