B1325
DTC B1325
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (with HP2) (Initial Inspection and Diagnostic Overview)Diagnostic System Check - Vehicle (without HP2) (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptors
DTC B1325 03
- Device Power Circuit Voltage Below Threshold -12V
DTC B1325 07
- Device Power Circuit Voltage Above Threshold -12V
Diagnostic Fault Information
Circuit/System Description
The control modules on this vehicle monitor the battery voltage on the 12V battery positive (B+) voltage circuits. This vehicle has multiple modules that will set the DTC. For information about which modules, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code Descriptions).
Conditions for Running the DTC
* The 12V battery voltage supplied to the control modules is in the range of 7-26 volts.
* The engine is running.
Conditions for Setting the DTC
B1325 03
The control module detects that the 12V system voltage is less than 9 volts for 5 seconds.
B1325 07
The control module detects that the 12V system voltage is greater than 18 volts for 5 seconds.
Action Taken When the DTC Sets
* The control module immediately disables all outputs when an out of range voltage condition has been detected, with the exception of GMLAN, which is disabled after a 3 minute delay.
* The setting of other DTCs is inhibited.
Conditions for Clearing the DTC
The DTC clears when the malfunction is no longer present.
Diagnostic Aids
* A high or low voltage value in multiple modules indicates a concern in the charging system.
* Overcharging with a battery charger can cause this DTC to set.
Reference Information
Schematic Reference
* Control Module References (Programming and Relearning)
* Power Distribution Schematics ([1][2]Electrical Diagrams)
* Ground Distribution Schematics ()
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Charging System Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Testing
1. Engine running, accessories OFF, measure and record the battery voltage at the 12V battery terminals. The voltage should be between 12.6 and 15.0 volts.
• If not within the specified range, refer to Charging System Test (Charging System Test).
2. Ignition OFF, disconnect the harness connectors at the appropriate module.
3. Ignition OFF and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 5 ohms between the ground circuit and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
4. Verify that a test lamp illuminates between the 12V B+ circuit terminals and ground.
• If the test lamp does not illuminate, test the 12V B+ circuit for a short to ground or an open/high resistance.
5. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminals and ground.
• If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
6. If all circuits test normal, replace the appropriate module.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning) for the appropriate module replacement, setup, and programming.