April/May 2002

Safety warning on trailer tracking

Braking specialists are concerned that some future independent trailer tracking systems could compromise vehicle safety because of the way batteries powering the trailer's GPS/GSM unit are recharged.

On some systems, the battery pack is recharged whenever the unit is hitched to a tractor, via a trickle feed through the electrical connection. TMC Innovations is the best known exponent of this, but its patented Susie Track uses the dedicated electrical connection powering the trailer lights, so doesn't interfere with the braking function.

Braking systems experts have told m.logistics that some other manufacturers may be tempted to tap into the ABS/EBS brake systems connector, ISO 7638, for the power feed. In certain circumstances this might raise concerns because the power-hungry GPS/GSM unit is invariably installed ahead of the ABS/EBS electronic control in the electrical circuit.

Whilst it may be possible to configure the system to do this perfectly safely, If the amps drop for whatever reason, the braking system is second in the queue for the available power and the ABS system, unbeknown to the driver, might not function as intended.

We were unable to clarify the situation as we went to press with our first issue, so we'll bring you an update as soon as we know more, but until then, at the least you should ask any trailer tracking equipment supplier about where the power is coming from to power the GPS/GSM unit, and how the ABS is ring-fenced.