What should I do if the red warning light at the front of my semi-trailer comes on or is blinking?

The following situations may occur:

  1. The red control light is off: (all functions, hydraulic as well as electrical, are operative; or the 24V voltage of the battery/NATO cable is absent; or the lighting is not switched on)
  2. The red control light is blinking: (speed signal does not show on the ASA printed circuit board, connection No. 23 blue/black)
  3. The red control light stays on without blinking: the pre-pressure is too low in 1 or more hydraulic steering circuits (red/blue/green/yellow).
  4. The red control light alternately blinks and stays on for 15 sec: the speed signal does not show and the pre-pressure is too low in 1 or more hydraulic steering circuits (red/blue/green/yellow).

The red light may come on for a few seconds when you steer the tractor to the left or right (e.g. when taking a bend).

After taking the bend and the tractor is back in the straight-ahead position, the light should automatically go off again. In this case no action is required.

If the light stays on there is not enough pre-pressure in the hydraulic steering system.

If your vehicle is equipped with manual steering you should use it to briefly steer left and right, then put it back in the automatic central position.

The red light will go off and now there is sufficient pre-pressure in the steering system.

Tip! This is best done during the coldest part of the day; if the temperature is rising the pressure in the hydraulic steering system will increase.

A blinking red light (situation 2) is always indicates the non-functioning of the manual steering and you must look for the solution of this malfunction in the electronics of the brake system or the cabling and/or connections between the ABS control unit and the ASA printed circuit board connection No. 23 (check electronics, cabling and electrical connections).

If the light is still blinking after the cabling has been checked we suggest you contact the Nooteboom service centre in Zwijndrecht or Wijchen to make an appointment in the workshop or to book a service mechanic.

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