It’s not even 10 years ago that the “electronic firepower” on a Japanese truck was minimal at best. Just about every system was controlled mechanically and electronic controls were few and far between. But the introduction of new exhaust gas emission rules in 2003 pushed the introduction of electronics into new territory. To achieve low enough emissions to meet the new regulation, electronic fuel injection was vital and the system needed plenty of information from around the truck to get the best result.
Such a high level of electronic integration had been available in European-made trucks for some time, they were almost one full exhaust gas emission control level ahead of us in Australia. Trucks and engines from the US were somewhere in between – electronic engine control had become the norm in the early 1990s, but there was very little integration into other vehicle systems outside of the power plant itself.
A recent test drive, carried out by Prime Mover, took two loaded UD trucks out of Sydney and south along the Princes Highway to gauge just how well the integration between engine systems and transmission systems work. The two trucks, a UD PK 17 280 and an MK 11 250, were both fitted with Allison automatic transmissions. In the case of the PK, it was the Allison 3060 P and on the MK the 2500. 
The idea of the road test was to assess the way the transmission “talks” to both the engine and other vehicle systems, and to see how well engine and transmission work together to produce the performance needed by a modern transport fleet and the 21st-century truck driver. The route offers an ideal combination of metro city driving, four-lane motorway driving and difficult winding country roads in undulating countryside.
One reason for the increase of electronic control systems over the past 10 years in trucks all over the world is the plunge in development costs. As the amount of electronics included in vehicles increased, production costs per unit decreased, making them available to a wider truck buying public. At the same time, car electronics were taking off at an even faster rate, so the systems were able to migrate from the mass car market into the, smaller, truck market.
The other major driver of change was the exponential improvement in the field of control systems and software, and their easy availability in just about every aspect of modern life. Once individual systems within the vehicle were being electronically controlled, ensuring they were communicating effectively was the next logical step – an important and useful method of vastly improving vehicle performance.
As a result, multiplex electrical systems came up, giving developers the ability to talk to everything on the truck using software systems that are able to distribute information, set priorities, monitor performance and make control system decisions on the fly many thousands of times a second.
These changes have revolutionised the way trucks work and made a significant difference the to the truck driver's lot. But the world of the truck technician has also changed. Equipment needed for a repair call out is no longer just a sledgehammer and oxy-acetylene gear. Now, the technician needs to bring a laptop, a sledgehammer and some oxy-acetylene gear.
Read more in the current issue of Prime Mover, out now.