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Keyword 82 and Keyword 2000 Data Line

The Keyword protocols utilize a single wire bi-directional data line between the modules and the scan tool. With this type of communication, a voltage level of less than 20 percent of B+ is considered a logic 0. A voltage level greater than 80 percent of B+ is considered a logic 1.

The message structure is a request and response arrangement that has some similarities to the UART system.

The modules on the Keyword 82 data line are:
^ Automatic Level Control Sensor
^ Memory Seat Module
^ Instrument Cluster
^ Heater and A/C Control
^ SIR Module
^ Power Steering Control Module
^ Sun Roof Actuator
^ Theft Deterrent Module (Immobilizer)

The control modules on the Keyword 2000 data line are:
^ Engine Control Module (ECM)
^ Transmission Control Module (TCM)
^ Electronic Brake/Traction Control Module