Test J: No Communication With Gem
NOTE:
After all repairs, clear DTCs and recheck system operation. See WIRING DIAGRAMS
for circuit identification and repair.
- Check Battery Junction Box (BJB) maxi-fuse No. 1 (50-amp). If fuse is okay, go to next step. If fuse is not okay, replace fuse. Clear DTCs and recheck system operation. If fuse fails again, check for short to power in Tan/Black wire between BJB and Central Junction Box (CJB). Repair circuit as necessary.
- Check CJB fuse No. 25 (7.5-amp). If fuse is okay, go to next step. If fuse is not okay, replace fuse. Clear DTCs and recheck system operation. If fuse fails again, check for short to ground in White/Yellow wire between CJB and GEM. Repair circuit as necessary.
- Measure voltage between ground and CJB fuse No. 25 (7.5-amp) fuse holder (input side). If more than 10 volts exist, go to next step. If 10 volts or less exist, repair open in Tan/Black wire (power feed). See POWER DISTRIBUTION article in WIRING DIAGRAMS.
- Turn ignition switch to LOCK position. Disconnect GEM 18-pin harness connector C283. Measure voltage between ground and GEM harness connector C283 terminal No. 11 (White/Yellow wire). See Figure . If more than 10 volts exist, go to next step. If 10 volts or less exist, repair open in White/Yellow wire between fuse junction panel and GEM.
- Turn ignition switch to LOCK position. Disconnect GEM 26-pin harness connector C280. Measure resistance between ground and GEM connector C280 terminal No. 14 (Black/White wire). See Fig 1 . Measure resistance between ground and terminal No. 26 (Black/White wire). If resistance is less than 5 ohms in both measurements, go to next step. If resistance is 5 ohms or more in either measurement, repair open in appropriate Black/White wire(s) between GEM connector C280 and ground. Ground point is located in left front engine compartment, near radiator.