A lot of workshops have experience with stability control systems and a lot of workshops have none, so Diesel Workshop is running a series of FAQs on EBS, TEBS, RSC, ABS, and EBS. The fitment of such systems has been sporadic in the past. This situation is about to change with the mandatory fitting of some form of stability control making its way through to law. Now anyone dealing with truck and trailer maintenance has to be up to speed with just what the implications are of fitting these kinds of systems onto a vehicle.
Diesel Workshop would like to thank and acknowledge the Australian Trucking Association’s (ATA) Technical Industry Council whose Technical Advisory Procedure (TAP) is the reference on which this article was based. The aim is to provide trucking operators with key information about the fitment and operation of stability control systems for improved vehicle safety.
Here are a few Frequently Asked Questions:
QUESTION: Can I retrofit stability control to my prime mover?
ANSWER: Yes and no. An EBS system with full functionality includes a steering angle sensor and additional controls within the brake system, putting it beyond almost all suppliers due to both complexity and cost. But basic stability control or roll stability control is far simpler and typically once automatic traction control is fitted, it requires an additional solenoid to manage the steer axle brakes and a new ABS Engine Control Unit (ECU), which has very specific mounting requirements.
QUESTION: Can I have a TEBS-equipped trailer and get benefits if I don’t have an EBS or ABS on my prime mover?
ANSWER: Yes. Provided the TEBS unit has a constant power supply, the benefits of ABS and RSC will be available. Additionally, a Trailer Response Management (TRM) system could be fitted to the dumb truck (i.e., no EBS) and this will produce a simple brake activation signal for the TEBS trailer.
QUESTION: If I have 12V prime movers with and without ABS and if I provide power to the TEBS units, are the benefits of ABS and RSC available?
ANSWER: Yes. The ABS, RSC and load share functions are independently available provided there is a constant power supply and the TEBS unit is a multi-volt unit or 12V capable.
QUESTION: Is EBS available for multi trailer combinations?
ANSWER: Yes, but for the best results, a CAN router or repeater should be fitted to all trailers. For dumb trucks (i.e., no EBS signal available), a TRM unit can be fitted to the truck to provide a CAN signal to the trailers. This will be generated from the pneumatic signal for trailers towed by conventional prime movers.
QUESTION: Do I have to have disc brakes to specify TEBS?
ANSWER: No. The TEBS system is independent of brake type. With the introduction ADR38/04, it became a mandatory requirement that ABS-equipped units are also fitted with automatic adjusting brakes. This should also apply to retrofitted ABS or stability systems. Refer to Vehicle Standards Bulletin number 6 (VSB6) for further guidance. TEBS also needs to be set up correctly at installation to adjust for the different elements in the foundation brake system.
QUESTION: Is my truck supplier providing power and CAN signals at the correct voltages?
ANSWER: Not always. It is particularly an issue with European truck models where a 24V to 12V power converter is being used. The CAN signal provided will still match the original 24V power supply. This creates a voltage mismatch and the CAN signal will be ignored.