Recently, we have seen many cases of a seemingly routine procedure going wrong from a simple lack of knowledge. To most technicians, brake servicing is a routine daily process. It has become second nature. It only becomes an issue at the end of the brake pad replacement, when getting a firm brake pedal is impossible, and you now have an ABS fault code. The fault code C2A20 was logged in the Electro Hydraulic Braking System (EHBS).

The fault code was triggered because the system was not put into service mode prior to brake work commencing.

Under no circumstances should you put this vehicle into service mode after the fault has been logged, as this can cause irreversible damage to the control module and the code cannot be removed. Even by re- flashing the software.

To correct this situation:

• Connect a powerful charger or battery support to the car
• Turn on the ignition
• Fit a brake depressor to the brake pedal with a relatively strong push.

You should now hear the EHBS unit working now. Leave the vehicle for approximately 15 minutes ,or until the module stops working and the indicator has turned off. Then try to delete the fault and check for the correct operation of the braking system.

If that does not work:

• Check that the latest software is installed and carry out a brake bleed via diagnostics.
• Turn off the vehicle for 10 minutes.
• Turn on and keep the pedal depressed for more than 120 seconds, with at least 113 psi.
• Wait until the warning light turns off.
• Release the pedal and delete any codes.

If the fault still cannot be solved using these procedures, an OE diagnostic tool or remote diagnostics will be required, to reprogram the EHBS module

Most technicians will only go to the diagnostic tool for service mode when working on the electric parking brake, but not when replacing front brake components. Always check if the braking system requires any special functionality when performing any brake service operations.

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