Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Cadillac >> 1998 >> Catera >> Repair and Diagnosis >> External Pages >> Different car >> Section 16 (Body Control Module) >> Diagnosis & Repair >> DTC B1970, Exterior Light Power Fault >> Notes

DTC B1970, Exterior Light Power Fault: Notes

WARNING: This page is about a different car, the 1997 Cadillac Catera. However, it is still accessible from the selected car via links, so may be relevant.

BCM commands exterior lights on by energizing low beam and parking light relays. DTC B1970 will set when exterior lights have been commanded on and BCM detects a short to ground in Red/White wire between BCM and relays. When DTC B1970 is set, BCM will command exterior lights off, then attempt to turn exterior lights on until lights are no longer required. DTC B1970 will clear when exterior lights are commanded on and BCM senses exterior light power on after 2 consecutive monitoring cycles or when scan tool is used.

NOTE: If DTC B1970 is a history code, problem may be intermittent. Wiggle wires while performing the following test.