B1327

DTC B1327

Circuit Description
All vehicle modules monitor system voltage. The system voltage message is sent to other modules via Class 2 message. When the system voltage drops below the specified range DTC B1327 shall set within the affected module.

Conditions for Running the DTC
This DTC shall run only if the module has power, ground and the ignition is not in START mode. This DTC shall execute regardless of the battery voltage, except when the DTC B1390 is set current.

Conditions for Setting the DTC
^ This DTC shall be set as current when the voltage falls below 9.0 volts for 1.2 seconds.
^ When the vehicle exits START the module shall delay checking the voltage for 2 seconds.

Action Taken When the DTC Sets
^ A message shall be sent out on the class 2 lines to notify all other modules of low battery voltage.
^ The modules disable the setting of U codes and other DTCs.

Conditions for Clearing the DTC
^ The DTC will clear current status when the voltage is greater than 9.5 volts for 1.2 seconds.
^ A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.
^ Use the ON-Board clearing DTCs feature.
^ Use a scan tool.

Steps 1 - 8:

Test Description
The numbers below refer to the step numbers on the diagnostic table.
3. Tests for the proper voltage at battery positive voltage sense circuit of the module, if voltage is not within the proper operating range, the voltage sense circuit needs to be tested.
4. Tests the circuit for high resistance.
5. Tests for the proper ground circuit for the module.