Conditions For Setting DTC
WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. 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.