Circuit Description
The body control module (BCM) monitors the battery positive voltage and battery negative circuit voltage to determine if it is between 9-15 volts and sends this information out as a class 2 message to the vehicle theft deterrent (VTD).
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B1327 Device Power 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.
Conditions for Setting the DTC
This DTC shall be set as current when the voltage falls below 9 volts for 1.2 milliseconds.
Action Taken When the DTC Sets
A message shall be sent out on the class 2 lines to illuminate the charge indicator and security lamp.
Conditions for Clearing the MIL/DTC
In order to clear the DTC from a current status, the voltage shall be greater than 9.54 volts for 1,200 milliseconds.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests for the proper operation of the complete circuit.
-
This step tests for the proper operation of the signal input circuit.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Theft Deterrent System Schematics in Theft Deterrent Connector End View Reference: Computer/Integrating Systems Connector End Views in Computer/Integrating Systems | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Does the scan tool indicate the battery voltage is greater than the specified value? | 9 V | Go to Step 3 | Go to Charging System Test |
Replace the body control module (BCM). Refer to Control Module References in Computer/Integrating Systems. Did you complete the replacement? | -- | Go to Step 4 | -- | |
Does the DTC reset? | -- | Go to Step 2 | System OK | |
