Freightliner M2/SD, change SAE J560 Trailer Cable To Combo Stop/Turn Functionality

Applicable Vehicles

Freightliner M2+ and SD+ with SAE J560 7-way trailer cable

Issue

The SAE J560 7-way trailer cable provides a left turn lamp circuit and a right turn lamp circuit. If not otherwise specified at time of truck order, the default functionality of these circuits is turn signal only. This provides maximum compatibility with air-braked trailers.

In some applications, the customer may determine that the circuits need to support combined stop/turn signal functionality. Many un-braked or electrically-braked trailers use only combined stop/turn signal lamps at the rear of the trailer. Examples include boat trailers, light utility trailers, pole trailers, and RV trailers.

See the NOTES at the end of this solution for regulatory requirements that apply.

Solution

The functionality of the left turn and right turn circuits in the SAE J560 trailer cable can be changed by applying one of the following parameters to the SAM module with DiagnosticLink Professional:

• A0404572258-001 provides turn signal only functionality.
• A0404572158-001 provides combined stop/turn signal functionality.

This reprogramming does not change functionality of any other circuits in the SAE J560 trailer cable, including the stop lamp circuit.

NOTE 1: In the United States and Canada, regulations REQUIRE use of a red lamp for combined stop/turn lamp functionality and prohibit use of an amber (yellow) lamp for this purpose. Other countries may have similar regulations.

NOTE 2: The combined stop/turn lamp parameter is not appropriate for use on any air-braked trailer where an amber (yellow) turn signal lamp is mounted along the side of the trailer, even if the lamps used at the rear of the trailer are red.