DTC B1327: Device Power No. 1 Circuit Low
- Turn ignition on. Using scan tool, select BCM DATA DISPLAY and monitor BATTERY VOLTAGE. If scan tool displays less than 9 volts, go to next step. If scan tool displays 9 volts or more, problem is intermittent. Check for intermittent poor connection to BCM. See COMPONENT LOCATIONS . Repair as necessary and retest operation.
- Connect DVOM (backprobe) between ground and Gray 8-pin BCM connector J4 terminal "D" (Orange wire). See Fig 1. If voltage is less than 9 volts, go to next step. If voltage is 9 volts or more, check for open in Black wire between Gray 8-pin BCM connector J4 terminal "F" and ground. See WIRING DIAGRAMS . Repair as necessary and retest operation. If Black wire checks okay, go to step 4.
- Check for open or short to ground in Orange wire between Gray 8-pin BCM connector terminal "D" and BCM/CLUSTER fuse (15-amp), located in underhood fuse block. See WIRING DIAGRAMS . Repair as necessary and retest operation. If Orange wire checks okay, check for intermittent problem in charging system. See appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS. Repair as necessary and retest operation.
- Check for poor connection to BCM. Repair as necessary and retest operation. If BCM connection checks okay, replace BCM. See BODY CONTROL MODULE under REMOVAL & INSTALLATION. Retest operation.
Courtesy of GENERAL MOTORS CORP.