Circuit Description
The body control module (BCM) monitors vehicle system voltage. Also, other individual modules monitor system voltage. The BCM sends a system voltage message to other modules that do not monitor system voltage via Class 2 message.
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 16.0 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 low 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 | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Vehicle Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic Starting Point - Computer/Integrating Systems in Computer/Integrating Systems |
2 |
Does the scan tool indicate that DTC B1328 is current in more than 1 module? | -- | Go to Step 4 | Go to Step 3 |
3 | With a scan tool, observe the Battery Voltage Signal parameter in the BCM. Does the scan tool indicate that the voltage is greater than the specified value? | 16.0 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? | 16.0 V | Go to Step 5 | Go to Charging System Test |
5 |
Important: Perform the setup procedure for the module setting the code, if necessary. Replace the affected module. Refer to Diagnostic Starting Point - Computer/Integrating Systems in Computer/Integrating Systems. Did you complete the replacement? | -- | Go to Step 6 | -- |
6 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
