With Manufacturer's Scan Tool

Diagnosis, Fault Memory - Passat

Fault memory, reading

Check Fault memory

After connecting the VAG 1551 tester, the display alternates between the following operating modes:
1 - Rapid Data Transfer
2 - Blink Code Output

- turn on VAG 1551 printer with "print" button
- indicator lamp in button lights up
- switch ON ignition

[ Rapid data transfer HELP ]
[ Insert address word XX ]

- press button 1 to select operating mode "Rapid data transfer"
- display will appear as shown

[ Rapid data transfer Q ]
[ 01 - Engine electronics ]

- press buttons 0 and 1 to select "ENGINE ELECTRONICS"
- display will appear as shown
- press Q button to enter input

[ Rapid data transfer ]
[ Tester sends address word 01 ]

- display will come on briefly to indicate it has sent the address word 01 (check control unit versions)

[ 8AO907404 MOTOR -> ]
[ Coding 00 ]

- then the engine control unit will respond with an identification display which shows the part number, what system it controls, and when it was coded.

If display appears as shown instead:

[ Rapid data transfer HELP ]
[ Control unit does not answer! ]

- press HELP key to print out a list of possible failures - after eliminating causes of failure
- repeat all inputs from the beginning to obtain the engine control unit identification screen...then proceed

[ Rapid data transfer HELP ]
[ Select Function XX ]

- press -> button
- display will appear as shown

[ Rapid data transfer Q ]
[ 02 - Check fault memory ]

- press "0" and "2" buttons to select Function 02 "Check Fault memory"
- display will appear as shown

[ 2 faults recognized! ]
[ ]

or

[ No faults recognized ]
[ ]

- press Q button to enter input
- display will appear as shown
- press -> button
- stored faults are displayed and printed consecutively

After display and print out of the last fault
- press -> button
- select Function 06 to End Output, and press the Q key to enter that selection
- correct faults using the fault code table, electrical testing table, wiring diagrams, and output check diagnosis function
Multiple faults may be related, e.g.: low idle speed due to an inoperative idle stabilizer may also result in a Hall sender fault being generated.
For vehicles with an automatic transmission, you MUST return the Digimat system to the basic setting after the following repairs:
- engine removal or replacement
- removal/replacement/adjustment of the throttle body, throttle cable, or throttle valve potentiometer
- removal or replacement of the transmission ECU

If there is a complaint that has not registered a fault in the self diagnosis memory, perform further testing as per the troubleshooting guide.