Document ID: chunk:federal_register_of_legislation:F2025C00108:reg:4:p22
Version: federal_register_of_legislation:F2025C00108
Segment Type: reg
Provision Reference: reg 4 (pt 22/25)
Character Range: 150065–153258

current having a nominal voltage level of 12 volts or 24 volts.
     2.                            Each ISO 7638 connector must be wired to have the following functions:
Contact 1  +ve high current trailer solenoid valve supply;
Contact 2  +ve low current trailer electronic unit supply;
Contact 3  -ve low current trailer electronic unit supply;
Contact 4  -ve high current trailer solenoid valve supply; and
Contact 5  trailer warning signal, switched to -ve (e.g. contact 3 or contact 4) upon fault detection.
 1.                            Either the optical warning lamp specified in clause 1.2 of APPENDIX 2 or an additional yellow optical warning signal (appropriately labelled) must light up whenever contact 5 of an ISO 7638 connector is connected to ground or a -ve connector.
 2.                            The power supply provided by an ISO 7638 connector must be used exclusively for braking and running gear functions and that required for the transfer of trailer related information not transmitted via an electric 'Control Line'.
     1.                     However, in all cases, whenever power supplied by an ISO 7638 connector is used for the functions defined in this clause above, the braking system must have priority and be protected from an overload external to the braking system.  This protection must be a function of the braking system.  The power supply for all other functions must use other measures.

 1.                                  Electric 'Control Line' requirements
     1.                            Where the vehicle also provides an electric 'Control Signal' via an electric 'Control Line':
         1.                     The communications via the electric 'Control Line' must conform to ISO 11992‑1:2003 and ISO 11992‑2:2003 including its amendment 1:2007.
         2.                     The electric 'Control Line' must be a point-to-point type using a seven contact connector in accordance with ISO 7638‑1:2003 or ISO 7638‑2:2003; as per which, contact 6 must be wired for the CAN_H signal and contact 7 must be wired for the CAN_L signal.
         3.                     The electric 'Control Line' must meet the requirements of ISO 11992‑1:2003, including:
                1.       The wiring must be an unshielded twisted pair; and
                2.       The maximum cable length of the electric 'Control Line' within the vehicle must not exceed 15 m and the bus capacitance of the cable must not exceed 750 pF.
     2.                            The data contacts of an ISO 7638 connector incorporating an electric 'Control Line' must be used to transfer information exclusively for braking (including the 'Vehicle Stability Function' and 'Antilock System') and running gear (steering, tyres and suspension) functions as specified in ISO 11992‑2:2003.
         1.                     The braking functions have priority and must be maintained in the normal and failed modes.  The transmission of running gear information must not delay braking functions.
     3.                            When a power-driven vehicle is equipped with an electric 'Control Line' and electrically connected to a trailer equipped with an electric 'Control