Can we fix embedded intelligence?

Senior Tech Editor Rich Merritt observes that having embedded processors in everything from sensors to control valves can make maintenance dicey when it comes to fixing things around the house.

By Rich Merritt, Senior Technical Editor

MY WIFE'S 2005 Chrysler 300C Hemi has 22 embedded computers that control the engine, AWD transmission, and the seat memory module, among other things. The car is configured much like a modern distributed process control system, and that worries me a little. Who is going to fix it?

Each computer is a standalone device responsible for a certain area of the car. Each responds to inputs from the supervisory control system (the driver), can carry out its control duties without constant reminders, and a failure in one controller does not necessarily take down the entire system. Just like a modern DCS.

And, like modern control systems, it comes with diagnostic and troubleshooting tools that work over the Internet.

For example, our seat memory module failed. This module remembers the seat’s last position, raises the steering wheel and moves the seat back when you open the door, and restores the seat position the next time you get in. It has about 500 other functions which we have yet to figure out. Just like a modern fieldbus module or smart motor drive.

When the module failed, we took the Hemi to the local Chrysler dealer, where they hooked it up to the Five Star computer system, diagnosed the problem in Detroit, and downloaded the appropriate software fix. It was in and out in 10 minutes. It took longer to process the warranty paperwork than it took to fix the problem.

The only difference I see between Chrysler’s system and process control equipment is that you don’t have to drive your control system to a dealer; you can obtain diagnostics and downloads directly, via the Internet or from built-in functions.

Chrysler spent $230 million to develop diagnostic equipment for its dealerships, including a massive computer network linking customers, dealers, suppliers and departments within Chrysler. Using this system, repairs can be diagnosed quickly and correctly, while sudden clusters of repairs can be seen immediately by design engineers so production changes take place more rapidly.

Ken Valentine, service manager at First Avenue Chrysler in Cedar Rapids, told me that many problems in some 2005 cars cannot be diagnosed and repaired without the Five Star system. “We plug it in, and the diagnostic system tells us what’s wrong and how to fix it,” he says. “Without the system, sometimes we’re lost.”

Actually, the Hemi went in three times to get fixed. The first time, the Five Star system wasn’t working yet, so they simply replaced the seat control module. That lasted three days, so I took it back. Their Five Star system still wasn’t working, so they drove the car down to a nearby Dodge dealer, and tried to use Dodge diagnostics. Alas, Dodge Magnums and 300Cs may look alike, but they apparently have slightly different diagnostics. The third time was the charm: with the correct diagnostic system, the mechanic easily fixed the problem.

It concerns me that I am forever tied to the Chrysler dealer for repairs, because no one else can work on it – not even a Dodge dealer. Just like a modern DCS.

My most recent toy car was a 1994 Mitsubishi 3000GT VR4 twin turbo. I was baffled by that car for the longest time, but we eventually figured out where all the intercooler hoses and vacuum lines and boost controls and air/fuel controllers went and why. We successfully fixed it when it broke, and modified the engine up to about 500 hp. It was a marvelous piece of engineering that was complex but still understandable and work-on-able.

As for the Hemi, I don’t know. Having 22 computers controlling everything is daunting. Where do you start? How do you diagnose at home? My answer was to buy an extended warranty that covers the car for the next five years, and entrust it to Chrysler’s diagnostic computer.

I suspect the same solution applies to modern control systems. Although many plants once were able to maintain and repair control systems themselves, those days are long gone. Having embedded processors in everything from sensors to control valves makes in-house maintenance dicey. Where do you start?

You start by buying the equivalent of an automotive extended warranty, of course, and relying on built-in and Internet-based diagnostics. Maintenance of cars and process controls both come down to a big question: Who do you trust to still be around for the life of the system?

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