GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2004 🢒 Regal 🢒 DTC 🢒 DTC B1328

Circuit Description

All vehicle modules monitor system voltage. The system voltage message is sent to other modules via Class 2 message. When the system voltage is above the specified range DTC B1328 shall set within the affected module.

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 will set as current when the voltage is greater than 15.9 volts for 1.2 seconds.

Action Taken When the DTC Sets
    • A message shall be sent out on the class 2 lines to notify all other modules of high than normal 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.

Diagnostic Aids

Using a battery charger to jumpstart the vehicle may set DTC B1328 as a history code.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Tests for the proper voltage at battery positive voltage sense circuit of the module, if voltage is not within the proper operating range, the voltage sense circuit needs to be tested.

    2.

  2. Tests for the poor connections at the harness connector and module.

Step

Action

Value(s)

Yes

No

Schematic Reference: Starting and Charging Schematics or Power Distribution Schematics in Wiring Systems

1

Did you perform the Engine Electrical Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Engine Electrical

2

  1. Turn OFF the ignition.
  2. Disconnect the harness connector of the module setting DTC.
  3. Turn ON the ignition, with the engine ON.
  4. With a DMM, measure the battery positive voltage circuit of the module setting the DTC and the ground circuit of the module setting the DTC.

Does the voltage measure less than the specified value?

15.5 V

Go to Step 3

Go to Charging System Test

3

Inspect for poor connections at the harness connector of the module setting the DTC. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

15.5 V

Go to Step 5

Go to Step 4

4

Important: Perform the setup procedure for the module setting the code, if necessary.

Replace the module setting the DTC. Refer to Control Module References in Body Control System.

Did you complete the replacement?

--

Go to Step 5

--

5
  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