Mahle's portable digital testing assistant.

According to Ben Shirey, manager, Diagnostic Engineering, Mahle Powertrain (Novi, Ml; www.us.mahle.com), "Durability and battery life have always been problems with portable testers." This is especially true since they most often take the form of ruggedized laptop computers that can draw 25 W just for the processor, and more than two amps from the vehicle being tested. This means more than one unit must be available so units can be recharged as they run low on power. Mahle Powertrain thinks it has an answer to this problem.

It is a Windows-enabled PDA that sits in a ballistic nylon case filled with foam and a vehicle communications card with a standard J1962 connector. The unit is light, can take a fall without damage, and it doesn't lose its charge as readily as the PC tester. "It can go 12 hours on its own battery, and--when you plug it into the vehicle--it can be kept fully charged even if it's continually running at a 25% duty cycle," says Shirey. That's because the processor runs at 300 milliwatts (a 400-mW version is coming, and a 600-mW version is on the horizon), and draws very little amperage in comparison. And, since vehicle test protocols change as often as geologic eras, the tester can be updated by swapping out PDAs.

"The tester runs the same tests we do on a full-blown PC," says Shirey, "because we kept the software lean and efficient so it can quickly run in the limited processor resources of your typical PDA." This means the unit can run as many as 200 discrete tests in under two minutes. Its enhanced portability also means it can go where PC-based units can't, like on the line for in-process testing that validates systems before they are buttoned up behind trim panels and other components. Mahle also can produce a unit with a built-in scanner that reads the VIN of the vehicle, downloads the proper software protocols for that particular vehicle, and uses it to test that vehicle. Says Shirey: "A unit like this can match the high-pressure injector profiles on diesel vehicles to the powertrain control module to speed the adaptive learning process by downloading the pertinent information from an offline database in the plant." The PDA's portability also means it can be used to test systems and components before they are delivered to the line.

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In addition, a derivative has been built that uses a PDA motherboard and the vehicle communications card to create a low-cost data recorder. One German OEM currently uses it to record data from road tests of its top line car, which eliminates the need for the driver to record his subjective impressions. A similar unit has been developed for in-field testing that would either record or upload through a cell modem data that meet pre-set alert triggers.--CAS