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STEP 3: Blink code identification and system response

  1. If you already know how to read ABS Blink Codes from the ECU in question, please go straight to STEP 4: Blink code list
  2. If you are unsure how to read ABS Blink Codes from the ECU, start by familiarising yourself with the diagram below, and then, where appropriate, follow the step by step procedure in the table
  3. Please ensure all necessary Health and Safety precautions are implemented before commencing any repair work

Knorr-Bremse A6 System ECU



System Response

Notes / Comments



Establishing whether any faults are present.



The ABS Warning Lamp is triggered when the towing vehicle's ignition is switched on





Connect a Blink Code Adapter Switch (Part No. EZ1022) to the diagnostic socket fitted inside the second chamber of the ECU housing (accessed by lifting the lid of the ECU).






Switch Ignition ON (ECU powered).

Wait for at least 1 second,

Then press the Diagnostic Push Button (on the Blink Code Adapter Switch) and hold for between 2 and 5 seconds, as shown in the diagram above,

Then release button.


The ABS Indicator Lamp will illuminate whilst the button is pressed, and go out when it is released.

The ECU will then transmit Blink Codes for any faults recorded on the ECU. The codes are displayed on the built-in LED in the Blink Code Adapter Switch, the LED built into the ECU, and the towing vehicle's dashboard warning lamp.

See Step IV below (and above diagram) for how to interpret the ABS Indicator Lamp flashes.



Count the flashes from the ABS Indicator Lamp.

Write down only the first 4 or 5 Blink Codes for faults recorded on the ECU (there may be several stored in the memory).

The first code displayed is for the configuration of the system (see above diagram), following which faults are shown as Blink Codes.





Turn Ignition OFF

Determine if faults recorded in III above are active or stored:





Active Faults: Will reappear (repeat) after any Blink Codes have been deleted from the ECU.

Stored Faults: Will be cleared when Blink Codes are deleted from ECU.

NOTE: Last fault stored is first fault displayed.




Clearing ECU fault memory:

Whilst pressing the Diagnostic Push Button, switch ignition ON, and hold button for a further 2 seconds.

Release button and the memory is cleared.

The ECU self-configures after the memory has been cleared.

The ECU self-configures to the status of the system at the time of ‘powering up’ and so any component connected after configuration has taken place will not be recognised by the ECU.





Turn Ignition OFF






Repeat steps II and III above.

Record Faults (Blink Codes).

Only active faults will be shown now.


To identify blink codes, refer to the Blink Code List. Make the necessary repairs to active faults. Repeat Step V (Clearing ECU fault memory), then road test the vehicle. The warning light should go out.

If the warning light remains after road testing, go back and repeat steps II , III and VII again until the warning light does go out.

Record faults for future reference

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