B1328

DTC B1328

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 below 18 volts.

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 raises above 18 volts for 1200 milliseconds.

ACTION TAKEN WHEN THE DTC SETS
- The engine control module (ECM)/powertrain control module (PCM) will not illuminate the charge indicator.
- This DTC shall be set as current when the voltage raises above 18 volts for 1200 milliseconds.

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 less than 18 volts.

TEST DESCRIPTION

Steps 1-6:

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