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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 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

Wabco Vario C2 version ECU

Vario C2 ECU with lid open

Test plug - test position

Test plug - storage position

Wabco Vario C2 version ECU


When a fault occurs in the ABS, the dashboard ABS warning light indicates a problem, and the fault is stored in the memory of the ECU. The ECU blink codes will help you determine what the problem is.

The test plug for activating the blink code system and the lamp that flashes the codes, are located inside the ECU (see top diagram above). If the test plug is missing, the blink codes can be activated by connecting pin 6 to pin 10 on the black module in the ECU.


There are two types of faults that can be stored in the ECU memory:

Intermittent faults, and
Existing faults

A stored, or intermittent fault, identifies a failure that did occur but does not exist at


present. Examples could be a loose wire or erratic sensor signal, which could occur whilst the vehicle is in motion. A stored, or intermittent fault, can be erased from the ECU memory. It can be difficult to locate and repair an intermittent fault because you may not be able to easily see the cause of the problem. Keep a record of intermittent faults before you erase them to help isolate the problem.

An existing fault is a problem that exists currently. it is stored in the ECU memory, and cannot be erased until you correct the problem.

There can be more than one fault stored in the memory of the ECU. Faults are stored in numerical order. You must erase the fault shown before you can see the next fault. You cannot erase a fault if it has not been corrected. When you have erased all the faults, the ECU will show the blink code for, "No Faults - System O.K." (X-0-0) where 'X' represents the configuration code, a number from 1 to 9.




System Response




Turn Ignition ON

Possible responses:

ABS indicator lamp comes on momentarily then goes out, indicating System O.K.

ABS indicator lamp does not light, indicating possible wiring fault or burned-out bulb

ABS indicator lamp stays on, indicating:

1. Fault, or faults, in the system

- - - - - - - - - - - - - - - - - - 2. Sensor fault during last operation

3. Faults cleared from ECU, but vehicle not driven
4. ECU disconnected


No recognizable active faults in the ABS. No action required- - - - - - - - - - - - - - -

Inspect wiring. Inspect bulb. Make necessary repairs- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


Continue blink code diagnostics (Go to Step II below)

Continue blink code diagnostics (Go to Step II below)- - - - - - - - - - - - - - - -

Drive vehicle — lamp will go out when vehicle exceeds 7 kph

Connect ECU


With Ignition ON, Remove the black test plug from the storage position on the ECU, and put the plug in the test position (see above)

ABS indicator lamp begins Blink Code cycle.




Count the flashes to determine the blink code

The blink code lamp will remain on for approximately five seconds after you install the test plug, then...

2.5 second pause (light off) then...

2.5 second Start Pulse, (light on) then...

2.5 second pause (light off) then...

First Digit: 1 - 9 flashes, this is the configuration code, then...

2.5 second pause (light off) then...

Second Digit: 0 - 4 flashes, then...

2.5 second pause (light off) then ...

Third Digit: 0 - 15 flashes, then...

2.5 second end pause (light off)...

All of which is described visually in the diagram immediately above this table


To find the definition for a blink code refer to the Blink Code List



Determine if a fault recorded in III above is existing or stored:





Existing 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.




Clearing ECU fault memory:

While the blink code is flashing, remove the test plug from the test position and wait until the flashing stops.

Disconnect power to the ECU by removing thee white plug from the white module, then, connect the power again

Put the test plug back in position

If the same blink code shows again, then you know the problem is an existing fault. You must correct the problem before you can erase the fault and check for other faults. Use the Blink Code List to determine what the problem is and how to correct it. Make sure you disconnect power from the ECU before you make repairs or you will cause new faults to be recorded.

If a new blink code shows, then you know that the first problem was an intermittent fault or that your repairs have corrected the first problem





Repeat the above steps until you see the code that indicates "No Faults - System O.K." (X-0-0)




Road test the vehicle. The dashboard ABS warning light should go out.

If the warning light remains after road testing, go back and repeat the above steps until the warning light does go out.

Record faults for future reference.


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