B1327

DTC B1327

CIRCUIT DESCRIPTION




The body control module (BCM) has an internal voltage sensor with a dedicated circuit that checks the battery positive voltage and battery negative circuit voltage to determine if it is above 8.7 volts.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC B1327 Device Power 1 Circuit Low

CONDITIONS FOR RUNNING THE DTC
This DTC shall run only if the BCM has power, ground and the ignition is not in START mode. This DTC shall execute regardless of the battery voltage.

CONDITIONS FOR SETTING THE DTC
- This DTC shall be set as current when the voltage falls below 8.7 volts for 1,200 milliseconds.
- When the vehicle exits START the BCM shall delay checking the voltage for 2 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The engine control module (ECM) / powertrain control module (PCM) will not illuminate the charge indicator.
- A message shall be sent out on the class 2 lines to notify all other modules of low battery voltage.

CONDITIONS FOR CLEARING THE MIL/DTC
In order to clear the DTC from a current status the ignition must be cycled and the voltage shall be greater than 9.0 volts.

TEST DESCRIPTION

Steps 1-7:

The number below refers to the step number on the diagnostic table.
3. Compares battery voltage with the voltage that the BCM calculates.