When Monitored And Set Condition:
WARNING: This page is about a different car, the 2003 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.
When Monitored: With the ignition in the Run or Start position the module monitors the Run - Start circuit for proper system voltage.
Set Condition: The code will set, if the voltage on the Run - Start circuit drops below approximately 4.5 volts for the ACM.