Battery Telltale

The battery telltale is illuminated by instrument cluster when it receives a command from the PCM on 4-cylinder models, or the BCM on V6 models. The ECM sends a message to BCM through the CAN serial data link indicating to driver that there may be a problem in the charging system. For a system check, battery telltale indicator will illuminate for about 3 seconds during engine start-up until PCM or ECM senses voltage output by the generator. For additional charging system information, see appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS.