BCM Code B420: Retained Accessory Power Relays Circuit: Notes
WARNING: This page is about a different car, the 1990 Cadillac Seville and 1990 Cadillac Eldorado. However, it is still accessible from the selected car via links, so may be relevant.
If relays could not be heard or felt switching each 3 seconds with BO03 selected, then Retained Accessory Power (RAP) relay circuits are suspect.
NOTE:
Test number refers to test number on diagnostic chart.
Test Number 1) Checks for normal RAP functions, and checks for faults in RAP circuits.