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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 Gamma CP System ECU



System Response

Notes / Comments



Connect a switch (Diagnostic Push Button) between the pin labelled 'DIA L' of the ECU and Ground



Blink Code display (i.e. a sequence of flashes) may be initiated.

The Blink Code will be displayed on either the Dashboard ABS Warning Lamp (INA) or the Traction Control Warning Lamp (ASR). Consult the Vehicle Manufacturer’s Handbook to establish which lamp is used and where it is located.

In the absence of the Vehicle Manufacturer’s Handbook, a bulb with a maximum power of 10 W can be connected between Ground and either the INA or ASR lamp pin of the ECU (see appropriate wiring diagram).





Switch Ignition ON (ECU powered).

Wait at least 1 second,

Then press Diagnostic Push Button for between 2 and 5 seconds,

Then release button

ABS indicator lamp begins flashing Blink Code(s)




Count the flashes to determine the Blink Code.

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

First Block: 2 or 5 flashes, Pause...

Second Block: 2 flashes, - - - Pause...


Third Block: 1 - 21 flashes, Pause...- - - - - - - - - - - - - - - - - -

Fourth Block: 1 - 21 flashes, Pause...

The first two blocks of flashes indicate the configuration. - -



The third block indicates any faults in the front left or rear right Sensors and Modulators.

The fourth block indicates any faults in the front right or rear left Sensors and Modulators.



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 3 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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