Abstract: An improved hand held starting/charging system tester. According to one aspect of the present invention, the portable handheld tester includes a connector to which various test cables can be removably connected to the tester. Detection circuitry within the tester determines which of several types of test cable is connected to the tester before testing. According to another aspect of the present invention, the portable handheld tester includes an improved user interface that permits a user to review test data from previously performed tests and further permits a user to either skip a previously performed test (thereby retaining the previously collected data for that test) or re-do the test (thereby collecting new data for that test). According to yet another aspect of the present invention, the portable handheld tester that performs a more complete set of tests of the starting/charging system.

Abstract: An improved code reader for reading and displaying OBD II diagnostic codes. The code reader displays textual diagnosis descriptions corresponding to diagnostic codes. Although the code reader preferably has a display having fewer available display characters than the number of characters in the OBD II textual diagnosis descriptions, the code reader can display both an OBD II code and the textual diagnosis description corresponding to a selected OBD II code. This is accomplished using code giving the appearance that the textual diagnosis description corresponding to the selected OBD II code is either streaming on the display or scrolling on the display.

Abstract: An improved hand held starting/charging system tester. According to one aspect of the present invention, the portable handheld tester includes a connector to which various test cables can be removably connected to the tester. Detection circuitry within the tester determines which of several types of test cable is connected to the tester before testing. According to another aspect of the present invention, the portable handheld tester includes an improved user interface that permits a user to review test data from previously performed tests and further permits a user to either skip a previously performed test (thereby retaining the previously collected data for that test) or re-do the test (thereby collecting new data for that test). According to yet another aspect of the present invention, the portable handheld tester that performs a more complete set of tests of the starting/charging system.

Abstract: An improved scan tool, e.g., for OBD II. According to one aspect of the present invention, the improved scan tool uses a novel method of determining the proper protocol to use to communicate with a vehicle computer network. According to another aspect of the present invention, the improved scan tool determines and automatically recovers from a communications drop-out.

Abstract: A method of measuring a condition of a battery is disclosed comprising the steps of: inducing an AC signal across the terminals of the battery by applying an AC current load thereto; measuring the induced AC signal and converting it to a first voltage potential signal which is a measure of the battery's internal resistance; applying the first voltage potential signal across a voltage divider network calibrated in accordance with a predetermined battery rating scale to render a multiplicity of second voltage potential signals at a corresponding multiplicity of taps along the voltage divider network, values of the second voltage potential signals being representative of the calibrated battery rating scale; and sequentially selecting the second voltage potential signals along the taps for comparison with a threshold voltage potential signal to determine a measure of the condition of the battery.