Anti-lock brake system (ABS)Anti-lock brake system (ABS) - Warning and indicator lamps - Instruments and warning/indicator lamps - Controls - Audi A4 Owner's Manual - Audi A4

The warning lamp monitors the ABS and the electronic differential lock (EDL).

The warning lamp few seconds when the ignition is switched on and while the engine is being started. lights up for a few seconds when the ignition is switched on and while the engine is being started. The lamp goes out again once the system has run through an automatic test sequence.

There is a fault in the ABS if:

  • • the warning lamp light up when the ignition is switched on, does not light up when the ignition is switched on,
  • • the warning lamp does not go out again after a few seconds,
  • • the warning lamp lights up when the vehicle is moving.

The vehicle can still be braked in the normal way (except that the ABS control function is out of action). Please take the vehicle to a qualified workshop as soon as possible. For further information on the ABS.

If a fault occurs in the ABS, the ESP warning lamp will also light up.

Fault in the main brake system

If the ABS warning lamp together with the brake warning lamp lights up together with the brake warning lamp ⇒ page 32, this indicates a fault in the ABS function, and possibly a malfunction ⇒ page 32, this indicates a fault in the ABS function, and possibly a malfunction in the main brake system as well ⇒ If there is a malfunction in the brake system the symbol.

If there is a malfunction in the brake system the symbol Please refer to. will light up in the instrument cluster. Please refer to.

Fault on the electronic differential lock (EDL)

The EDL works in conjunction with the ABS. If a malfunction should occur in the EDL, this is indicated by the ABS warning lamp workshop as soon as possible. For further information on the EDL.. Please take the vehicle to a qualified workshop as soon as possible. For further information on the EDL.

WARNING

  • • Before opening the bonnet and checking the brake fluid level, observe the warning information on, “Working on components in the engine compartment”.
  • • If the brake warning lamp with the ABS warning lamp should light up together with the ABS warning lamp and check the brake fluid level in the reservoir. If the fluid level has dropped, stop the vehicle immediately and check the brake fluid level in the reservoir. If the fluid level has dropped below the "MIN" mark you must not drive on - otherwise there may be an increased accident risk. You should obtain professional assistance.
  • • If the brake fluid level is OK, the fault in the brake system may have been caused by a failure of the ABS control function. As a result the rear wheels can lock relatively easily when braking. This could cause the tail of the vehicle to skid sideways. Drive carefully to the nearest qualified workshop and have the fault rectified.