The code(s) stored in the PCM's memory can be read either through a hand held diagnostic scanner plugged in the ALDL connector or by counting the number of flashes of the SERVICE ENGINE SOON telltale lamp when the diagnostic terminal of the ALDL connector is grounded. The ALDL connector terminal "B" (diagnostic terminal) is the second terminal from the right of the ALDL connector's top row. The terminal is most easily grounded by connecting it to terminal "A" (internal PCM ground), the terminal to the right of terminal "B" on the top row of the ALDL connector.
Once terminals "A" and "B" have been connected, the ignition switch must be moved to the "ON" position, with the engine not running. At this point, the SERVICE ENGINE SOON telltale lamp should flash code 12 three times consecutively. This would be the following flash sequence: Flash, pause, flash-flash, long pause, flash, pause, flash-flash, long pause, flash, pause, flash-flash. Code 12 indicates that the PCM's diagnostic system is operating. If code 12 is not indicated, a problem is present within the diagnostic system itself.
Try that and let me know what code's you have.
Saturday, July 31st, 2010 AT 8:00 PM
