CAN - Bus

ABS/EDL and ABS/EDL/ASR ITT Mark 20 IE

Required special tools and operating instructions





^ VAG1551 Scan Tool

Notes:
^ Instead of scan tool VAG1551, vehicle system tester VAG1552 can also be used, however no printout is possible.
^ All functions of the VAG1551/1552 can also be conducted with the tester VAS5051.





^ VAG1551/3 Diagnostic wire

- Determine how many control modules are connected to the CAN - Bus.
- Check control module multi-pin connector for proper fit.
- Connect scan tool VAG1551/1552 and press 0 button twice for function "Automatic Test Procedure."
- Before checking Bus - Lines make sure there is no functional interference to the control modules connected to the Bus.
- If there is functional interference, repair that first.
- Note malfunctions and erase DTC memory of all control modules.
- Press buttons 0 and 6 for function "End output" and confirm input with Q - button.
- Repair functional interferences based on DTC table in the corresponding Repair Informtion.

- If all functional interferences are eliminated and the communication of control module is still interrupted, check CAN - Bus wiring.
- Switch ignition off.





- Disconnect control modules connected to Bus - Lines and check Bus - Lines for open circuit. - Electrical Wiring Diagrams, Troubleshooting & Component Locations binder





- Check CAN - Bus wiring with regards to short between wires, to positive and to ground.
- If a malfunction is not found in the CAN - Bus wiring, check if a control module is causing malfunction.
- Reconnect all control modules and replace one control module (use process of elimination).
- Code control module per appropriate Repair Information.
- Connect VAG1551 or VAG1552.
- Switch on ignition and erase DTC memory of control module just connected.
- End output of scan tool with function 06 "End output."
- Switch ignition off and then on again.
- Leave ignition switched on for 10 seconds. Check DTC memory of control modules connected to CAN - Bus using scan tool.
- If a malfunction which affects CAN - Bus is found, replace control module which was just replaced with old one and replace next control module. Repeat the described procedure as necessary.