GM Service Manual Online
For 1990-2009 cars only

Circuit 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. This vehicle has multiple modules that will set this DTC. For more information on which modules refer to Diagnostic Trouble Code (DTC) List - Vehicle

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1328 Device Power 1 Circuit High

Conditions for Running the DTC

This DTC shall run only if the module has power, ground and the ignition is not in START mode. This DTC shall execute regardless of the battery voltage.

Conditions for Setting the DTC

This DTC shall be set as current when the voltage raises above 16 volts for 1.2 seconds.

Action Taken When the DTC Sets

    • A message shall be sent out to notify all other modules of high battery voltage.
    • The modules disable the setting of U codes and other DTCs.

Conditions for Clearing the DTC

    • The DTC will clear current status 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.
    • Use a scan tool.

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Operate the vehicle within the conditions for running DTC B1328.

Does the scan tool indicate that DTC B1328 is current in more than one module?

--

Go to Step 4

Go to Step 3

3

With a scan tool, observe the Battery Voltage Signal parameter in the body control module (BCM).

Does the scan tool indicate that the voltage is greater than the specified value?

16 V

Go to Step 5

Go to Charging System Test

4

With a scan tool, observe the Battery Voltage Signal parameter in the affected module.

Does the scan tool indicate that the voltage is greater than the specified value?

16 V

Go to Step 5

Go to Charging System Test

5

Replace the affected module. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 6

--

6

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK