Conditions For Setting DTC
WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
This DTC will set as current when the voltage is greater than 15.9 volts for 1.2 seconds and DTC B1390 is not set current in the affected module.