B1325

DTC B1325

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptors
DTC B1325 03
- Device Power Circuit Voltage Below Threshold

DTC B1325 07
- Device Power Circuit Voltage Above Threshold

Diagnostic Fault Information





Circuit/System Description

The control modules on this vehicle monitor the battery voltage on the battery positive (B+) voltage circuits. This vehicle has multiple modules that will set the DTC. For more information on which modules, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code Descriptions).

Conditions for Running the DTC

* The battery voltage supplied to the control module is in the range of 7-26 volts.
* The ignition is ON.

Conditions for Setting the DTC

B1325 03

The control module detects that the system voltage is less than 9 volts for 5 seconds.

B1325 07

The control module detects that the 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)
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 battery terminals. The voltage should be between 12.6 and 15.0 volts.

• If not within the specified range, refer to Charging System Test (Component Tests and General Diagnostics).

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 B+ circuit terminals and ground.

• If the test lamp does not illuminate, test the 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.