By Bernard J. Carr
Minor tasks such as engine oil replacement and tire rotation will soon require a skilled technician using a sophisticated tool. Some cars already have a manual reset function or use a pluggable diagnostic device to reset oil life monitors. The second example - tire rotation - will cause tire service professionals to rethink their approach to tire rotation, puncture repair and wheel replacement.
It is clear that vehicle technology does not wait for the repair industry to adopt new service procedures that may be required to support these tasks.
Most of us who digest the internal workings of an automobile today are quite familiar with onboard diagnostics (OBD) features and functions. As an industry, we have realized that with each passing decade, OBD functionality has increased. Another phase of the OBD plan - known as OBD level III - has been around for a few years at the bureaucratic level, and professionals and special interest groups are evaluating OBD-III's intentions and impacts.
From a regulator's standpoint, it is possible that the next step would require sending the results of on-vehicle monitor evaluations and diagnostic trouble codes only by wireless communication to state conservation agencies. Savings in vehicle owner time, state inspection, maintenance program administration and environmental impacts have been proposed with such plans. However, concerns of constituent privacy are raised, because many are troubled by the prospect of a vehicle-embedded electronic control module (ECM) with a wireless radio inside that monitors and communicates emission information to regulators. The result of OBD-III is not certain, however, from an intermittent problem-solving function. As industry professionals, we should not worry about wireless information wasting away on some government file server. Our focus should be on the vehicle network.
Automotive engineers are studying the requirements for the next generation of electronic systems and keeping a watchful eye on regulatory requirements, while continuing their quest for vehicle network advancement. First up for consideration is an examination of the vehicle's electrical system architecture. More powerful semiconductor strategies are incorporated into latest generation ECU technology, and these smart modules are in command of new electro-mechanical systems. To move data through these mammoths, a sophisticated network is required that can handle the message traffic. We do not have to look further than the controller area network (CAN). CAN is capable of moving more data at a higher data rate with good success. Today's existing bus speeds of 10-40kbps are being replaced with faster bus speeds of 80-500kbps. CAN digital networks move digital data, bit by bit, in thousands of bits per second. The practicality of this is that data is moved much quicker at 500,000 bits per second than it was at 10,000 bits per second. CAN has and will continue to serve the data sharing function between ECUs well.
Let's move this discussion ahead a few years where an even faster network is required to share data between X-by-wire systems, which is a technology that calls for the partial replacement of longtime, well-serving mechanical systems with electronic components. A simple example is throttle by wire - which most of you know is already on General Motors Corp., Ford Motor Co. and DaimlerChrysler AG cars - plus a host of other systems. The intent of a throttle by wire system is to replace the mechanical throttle cable with an electrical connection. Throttle by wire subsystem equipment includes throttle pedal position sensors and throttle blade actuators and sensors, and of course an impressive ECU to control the process.
Technology like this fuels our industry toward a standardized, time-critical and multi-solution network known as FlexRay. This network incorporates an electrical bus driver that has two circuits, with the most surprising feature being its speed. Up to a whopping 10 million bits per second can flow on this network in the form of point-to-point, linear and star topologies that can be further advanced to cascaded or hybrid branches. This network can move data faster than what we have seen on vehicles yet, which is about a thousand times quicker than some of today's OBD-II data links. Now maybe we can understand that with this communication, backbone systems such as drive-by-wire, steer-by-wire and brake-by-wire are possible.
As mentioned earlier, we've recently adopted other legislated communication protocol such as "Legislated Diagnostics On CAN" (ISO 15765-4). CAN has been used as an intra-vehicle network on some European makes since the early 1990s. We are now observing CAN protocol support of diagnostics on the standard 16-pin data link connector. With legislated CAN, the emission portion of the OBD-II system may be programmed to support more diagnostic data parameters, and the chain generic service tools can display this additional parameter identifier information. Leaders of this technology hope the additional parameters will assist the service diagnostician toward more efficient diagnostic results.
Generically speaking, when complex problems appear, most seasoned technicians use a diagnostic test device that supports dealership-level diagnostics. Many reasons drive their intent, with the most common being that problems do happen on other systems in the vehicle other than just the powertrain.
A powerful ECU and highly developed onboard diagnostic algorithms govern those systems. The combination of strong ECU input measurement, computing power, output control and ever-intelligent diagnostic algorithms are starting to show up as additional information for scan tool diagnostic trouble code test modes. Today, most systems detect opens, shorts, intermittents and erratic signals, and some even include status data within their data fields. System evolution calls for the aforementioned plus a symptom descriptor, which provides more information about the problem that the ECU has detected (see table below).
The symptom descriptor reflects the ECU's hardware capabilities and software features, which pinpoint failed conditions internally and serve to expedite the diagnostic process. The symptom descriptors in use today number more than 50, and they are grouped with respect to category: ECU, inputs, outputs and so forth.
Technology on the vehicle is changing, and there is no doubt that this will present challenging diagnostic situations. Technicians working with advanced subsystems that communicate on lightning-fast networks will have much more enhanced data to review in preparation of formulating his or her diagnostic process. This is the "detective" part of the occupation from which passionate technicians get satisfaction. Technicians of all levels possess a desire to know why and how, and it is possible that service and diagnostic equipment needs will change.
The automobile manufacturer and tool and equipment industries' challenge is to create a solution that satisfies technician use profile, fulfills service and diagnostic use cases, and fits in with the rules of business that the repair dealer deems important to its operations. Users would appreciate its simple, graphic interface so that one does not have to be an engineer to put the device to work. When carrying, connecting, viewing, powering or updating, users would be pleased with a functional ergonomic solution that makes sense for the service bay. The interface to the specialized vehicle network would likely be effective in both application and cost, and you may want to take advantage of a cable or no cable solution. Finally, a winning solution would allow easy authoring of dealer, aftermarket or user-derived functions intended for practical service and diagnostic software applications.
Such a service system should aspire to be a complete package that encompasses the service process. Tight integration of repair order, customer concern, warranty, bulletin, campaign, diagnostic, service article, field failure and training processes are key elements of an examination suite. Close assessment of each can identify areas of improvement in business practices and processes. True, some service industry approaches today are closely coupled, and they yield great results. Practically speaking, though, current service systems could be looked at as "tools," whereby tomorrow the service community may need a more cohesive enterprise approach that works for the technician, parts counterperson, service writer, shop foreman and repair dealer owner. The service community really needs an evaluation of what they do on a daily basis, to ratify the resulting work tasks into business rules - and then present the outcome in the form of a simple, effective, accurate and time-saving package.
Cars and trucks are now packed with more equipment than ever. We need the use of wireless technology figures to increase connectivity and play a better role in improving service processes. Multiplexed networks are expected to expand and carry more information. Diagnostic data is becoming more plentiful and supportive of emission and enhanced diagnostics. So all the key elements are either there now or will be soon, which can start reducing the gap between ever-expanding automotive technology and stationary service processes. What is missing might be the tie that simplifies the bind that automotive professionals go through as they work the service process each day. Accomplishing this connection starts with an assessment of the automotive professional's daily routine, with the goal of identifying areas of improvement so that productivity in all facets of the service process is increased.
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Bernard J. Carr is manager of automotive systems engineering at Vetronix (ETAS Group) in Santa Barbara, Calif. You may reach him at Bcarr@vetronix.com.
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