GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

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

DTC Descriptors

DTC B1325 03: Control Module Power Circuit Low Voltage

DTC B1325 07: Control Module Power Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

B+

B1325 03

B1325 03

--

--

Ground

--

B1325 03

--

--

Circuit/System Description

The control modules listed below monitor the voltage on the battery positive (B+) voltage circuits. High or low battery voltage prevents the modules from operating correctly.

    • Digital radio receiver (DRR)
    • Headlamp control module
    • Instrument panel cluster (IPC)
    • Liftgate control module
    • Mobile telephone control module
    • Parking assist control module
    • Passenger presence system (PPS)
    • Sensing and diagnostic module (SDM)
    • Steering column lock control module (SCLCM)
    • Trailer interface control module
    • Vehicle direction camera control module

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

B1325 03

The control module detects that the battery voltage is less than 9 V for 5 seconds.

B1325 07

The control module detects that the battery voltage is greater than 18 V for 5 seconds.

Action Taken When the DTC Sets

    • The control module immediately disables all outputs.
    • The setting of other DTCs is inhibited.

Conditions for Clearing the DTC

The DTC will pass 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 or jump starting can cause this DTC to set.

Reference Information

Schematic Reference

    •  Radio/Navigation System Schematics
    •  Headlight Leveling Schematics
    •  Instrument Cluster Schematics
    •  Liftgate Schematics
    •  Cellular Telephone Schematics
    •  Object Detection Schematics
    •  SIR Schematics
    •  Column Lock Schematics
    •  Exterior Lights Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Charging System Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References 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 V.
  2. If not within the specified range, refer to Charging System Test.
  3. Ignition OFF, disconnect the harness connectors at the appropriate module.
  4. Ignition OFF and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 5 Ω between the ground circuit terminals listed below and ground.
  5. • Terminal 13 X1 (DRR)
    • Terminal 1 X1 (Headlamp)
    • Terminal 16 X1 (IPC)
    • Terminal F X2 (Liftgate)
    • Terminal 2 X1 (Phone)
    • Terminal 7 X3 (Park)
    • Terminal 3 X1 (PPS)
    • Terminal 19 X1 (SDM)
    • Terminal 6 X1 (SCLCM)
    • Terminal 7 X1 (SCLCM)
    • Terminal 1 X2 (Trailer)
    • Terminal 2 X2 (Lane Departure)
    If greater than the specified range, test the ground circuit for an open/high resistance.
  6. Verify that a test lamp illuminates between the B+ circuit terminals listed below and ground.
  7. • Terminal 4 X1 (DRR)
    • Terminal 10 X1 (Headlamp)
    • Terminal 32 X1 (IPC)
    • Terminal M X2 (Liftgate)
    • Terminal 1 X1 (Phone, PPS)
    • Terminal 1 X3 (Park)
    • Terminal 9 X1 (SDM)
    • Terminal 5 X1 (SCLCM)
    • Terminal 3 X2 (Trailer)
    • Terminal 1 X2 (Lane Departure)
    If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  8. If all circuits test normal, replace the module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References - for the module replacement, setup, and programming.