DTC B1982 sets when the instrument cluster detects that the battery source voltage is above the normal range (15.5 volts) for more than 1.2 seconds. The instrument cluster determines battery source voltage from class 2 messages sent by the SBM, through the class 2 serial data line.

When DTC B1982 is set current, the instrument cluster displays may temporarily turn off in order to protect the circuit. The following DTCs do not set current in order to prevent setting erroneous DTCs:

1. Test the SBM for DTCs. If DTC B1982 is set as a history DTC, refer to Diagnostic System Check - Body Control System .
2. Test the other modules for the same Battery Voltage Low DTC. If DTC B1982 is set current, refer to Starter and Charging Cell 30 in Electrical Diagnosis.