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 Descriptor

DTC B1328: Device Voltage Circuit High - BCM, IPC

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

B+

B1327

B1327

--

--

Ground

--

B1327

--

--

Typical Scan Tool Data

Battery Voltage - BCM, IPC

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: Ignition ON, engine OFF.

Parameter Normal Value: 12.60 Volts

B+

0.00 Volts

0.00 Volts

12.60 Volts

Circuit/System Description

The control modules on this vehicle monitor system voltage through the battery positive voltage circuits. Damage to components, and incorrect data can occur when the voltage is out of range. If the battery voltage is high, the BCM and IPC may set DTC B1328.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The battery voltage is greater than 16 volts for 1.2 seconds.

Action Taken When the DTC Sets

    • A serial data message will be sent to notify other modules of high battery voltage.
    • The module disables the setting of other DTCs.

Conditions for Clearing the DTC

    • The DTC will pass when the voltage is less than 15.5 volts for 1.2 seconds.
    • A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.

Diagnostic Aids

    • Overcharging with a battery charger or jump starting may set this DTC.
    • A high voltage value in multiple modules indicates a concern in the charging system.

Reference Information

Schematic Reference

    •  Body Control System Schematics
    •  Instrument Cluster 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 Verification

  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.
  2. If not within the specified range, refer to Charging System Test .
  3. Observe the scan tool BCM or IPC Battery Voltage parameter. The reading should be between 12.60 and 15.00 volts.
  4. If not within the specified range, replace the appropriate control module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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