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Home >> Pontiac >> 1999 >> Firefly (CANADA) L4-1.3L >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Description and Operation >> Common OBD II Systems >> Serial Data Communications
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Serial Data Communications

Regulations require that all automobile manufacturers establish a common communications system. The communication Between the powertrain control module and the off-board diagnostic equipment (scan tool) is achieved on a serial communication line. Serial data is sent in linear form, one bit at a time, over the communication line.