B1983 Source/Battery Voltage Low - HVAC

CIRCUIT DESCRIPTION
DTC B1983 will set if the battery/source voltage is outside of its normal range, approx. 9.5 volts, for 2 seconds. If the source/battery voltage gets too low then the class 2 serial data bus will not operate, which will set false class 2 serial data codes. This DTC should not set if DTC B1981 (Battery Voltage low -Engine Running) is set.

This DTC should not be confuse with DTC B1981. DTC B1983 will set if the battery voltage drains to a level that the Air Conditioning Programmer (ACM) can no longer function properly.


TROUBLESHOOTING HINTS
1. Connect scan tool.
2. Monitor battery voltage with scan tool.
3. If the displayed battery voltage is greater then 10 volts replace the ACM.
4. If the displayed battery voltage is greater then 10 volts, measure voltage at ACM CKT 2640 terminal C3.
a. If voltage is less then 10 volts check CKT 2640 for an open or short to ground.
b. If CKT 2640 is OK, then check charging system voltage.
5. If the voltage measured at ACM connector C1 terminal C3 is above 10 volts then replace the ACM.