B1390
DTC B1390
CIRCUIT DESCRIPTION
The generator battery control module monitors the battery voltage for precision electrical power management. The generator battery control monitors both the battery positive voltage circuit and the ground circuit to determine system voltage. If there is a difference between the commanded system voltage and monitored voltage of more than 1 volt, then DTC B1390 will set.
DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC B1390 Device Voltage Reference Input 1 Circuit
CONDITIONS FOR RUNNING THE DTC
- Engine running for 30 seconds.
- This diagnostic shall be run every 100 ms.
CONDITIONS FOR SETTING THE DTC
The difference between the low precision battery voltage sense circuit reading and the high precision battery voltage sense circuit reading is greater than or equal to 1 volt for 10 seconds.
ACTION TAKEN WHEN THE DTC SETS
The generator battery control module will request the driver information center (DIC) message of Service Charging System.
The generator battery control module uses the less accurate battery positive voltage circuit for voltage readings.
CONDITIONS FOR CLEARING THE DTC
- During the current ignition cycle, the difference between the battery positive voltage circuit reading and the high precision battery voltage sense circuit reading is less than 1 volt.
- Clear the DTC with a scan tool.
DIAGNOSTIC AIDS
Recommended Action:
- Check the Batt + voltage wire for an open or short low condition.
- Check the Batt - ground wire for an open or short high condition.
- Clear the codes.
- Cycle the ignition.
IMPORTANT: You must cycle the ignition after clearing the DTC to turn OFF the DIC message of Service Charging System.
If a fault condition persists, replace the module.
TEST
