Division 3.3

In the case of a tractor equipped with two control lines as described in point 2.1.4.1.2 of Annex I, when electrically connected to a towed vehicle which is also equipped with two control lines, all of the following conditions shall be fulfilled:

1. 3.3.1.

   both signals shall be present at the coupling head and the towed vehicle shall use the electric control signal unless this signal is deemed to have failed. In this case the towed vehicle shall automatically switch to the pneumatic control line;

2. 3.3.2.

   each vehicle shall conform to the relevant provisions of Appendix 1 of Annex II for both electric and pneumatic control lines;

3. 3.3.3.

   F1when the electric control signal has exceeded the equivalent of 100 kPa for more than 1 second, the towed vehicle shall verify that a pneumatic signal is present; should no pneumatic signal be present, the driver shall be warned from the towed vehicle by the separate yellow warning signal specified in point 2.2.1.29.2 of Annex I.