Test C: No Communications With Electronic Brake/Traction Controls System
- Turn ignition on. Check ABS 1 and ABS 2 fuses (both 30-amp), and BCM/ECM/CRUISE/ABS fuse (10-amp), located in underhood fuse block. See COMPONENT LOCATIONS . If fuses are okay, go to next step. If any fuse is blown, replace fuse and check affected circuit for short to ground. See POWER DISTRIBUTION article in WIRING DIAGRAMS. Repair affected circuit as necessary and retest operation.
- Turn ignition off. Access EBTCM. See COMPONENT LOCATIONS . Disconnect Black 31-pin EBTCM connector. Turn ignition on. Connect test light between ground and EBTCM harness connector terminals No. 15 (Pink wire), No. 17 and 18 (both Red wires). If battery voltage is present on all circuits, go to next step. If battery voltage is not present on any circuit, check for open in affected circuit between EBTCM and ABS 1, ABS 2 or BCM/ECM/CRUISE/ABS fuse in underhood fuse block. Repair as necessary and retest.
- Check for open, short to ground or short to voltage in KW2000 circuit (Light Blue wire) between EBTCM harness connector terminal No. 11 and DLC terminal No. 12. See Figure and Fig 1
. Check for loose connection at DLC terminal No. 12. Repair DLC connection or KW2000 circuit as necessary and retest. If connection and KW2000 circuit is okay, check connections at EBTCM. If EBTCM connections are okay, replace EBTCM. See REMOVAL & INSTALLATION in appropriate ANTI-LOCK article in BRAKES.
Courtesy of GENERAL MOTORS CORP.