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Home >> Saturn >> 2005 >> Relay AWD >> Repair and Diagnosis >> Accessories & Equipment >> Communication Devices >> Computer/Integrating Systems >> Diagnostic Information And Procedures >> Power Mode Mismatch >> Circuit Description

Circuit Description

Normal vehicle serial data communications and module operations will not begin until the system power mode has been identified. Discrete wires from the ignition switch contacts are monitored by a module which acts as the power mode master (PMM) in order to determine the correct power mode. The module which is the PMM communicates the system power mode to all modules on the serial data lines. Refer to Body Control System Description and Operation  to identify which module is the PMM and the applicable power mode look up table.