Test X: No Communication With Generic Electronic Module

NOTE: Perform all voltage and resistance tests using an Digital Volt-Ohm Meter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use ohmmeter to isolate wiring harness shorts or opens.

Turn ignition switch to OFF position. Remove and inspect fuse No. 16 (15-amp) from Central Junction Box (CJB). CJB is located behind left side of instrument panel. See Figure. Turn ignition switch to RUN position. Measure voltage between ground and input side of fuse No. 16 (15-amp). If voltage is greater than 10 volts, go to next step. If voltage is less than 10 volts, repair open circuit in appropriate wire(s). See POWER DISTRIBUTION in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL. After repair, test system for normal operation.
Turn ignition switch to OFF position. Install fuse No. 16 (15-amp). Disconnect Generic Electronic Module (GEM) 12-pin harness connector C201a, located behind Central Junction Box (CJB). See Figure. Turn ignition switch to RUN position. Measure voltage between ground and GEM connector C201a terminal No. 4 (White/Red wire). See Figure. If voltage is greater than 10 volts, go to next step. If voltage is less than 10 volts, repair open circuit in White/Red wire. See POWER DISTRIBUTION in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL. After repair, test system for normal operation.
Turn ignition switch to OFF position. Measure resistance between ground and GEM connector C201a terminal No. 6 (Black/Light Green wire). See Figure. If resistance is 5 ohms or less, repair GEM module concern. See appropriate MODULE COMMUNICATION NETWORK article. If resistance is greater than 5 ohms, repair open circuit in Black/Light Green wire. See GROUND DISTRIBUTION in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL. After repair, test system for normal operation.