Test A: No Communication With Generic Electronic Module
- Turn ignition switch to RUN position. Measure voltage between ground and input side of Central Junction Box (CJB) fuses No. 32 (15-amp) and No. 39 (5-amp). CJB is located behind left side of instrument panel. See Fig 1
. If battery voltage exists at both input terminals, go to next step. If battery voltage does not exist at either input terminal, repair power supply circuit to appropriate fuse as necessary. See POWER DISTRIBUTION article in WIRING DIAGRAMS.
- Ensure fuses No. 32 and 39 are installed. Turn ignition switch to LOCK position. Disconnect Generic Electronic Module (GEM) 4-pin harness connector C291. GEM is located behind left side of instrument panel, next to CJB. Measure voltage between ground and GEM harness connector C291 terminal No. 1 (White/Yellow wire). See Fig 2
. If battery voltage exists, go to next step. If battery voltage does not exist, repair open in White/Yellow wire between GEM and fuse No. 39. See POWER DISTRIBUTION article in WIRING DIAGRAMS.
- Disconnect GEM 26-pin harness connector C352. Turn ignition switch to RUN position. Measure voltage between ground and GEM harness connector C352 terminal No. 22 (Black/Pink wire). See Fig 3
. If battery voltage exists, go to next step. If battery voltage does not exist, repair open in Black/Pink wire between GEM and fuse No. 32. See POWER DISTRIBUTION article in WIRING DIAGRAMS.
- Turn ignition switch to LOCK position. Measure resistance between ground and GEM harness connector C291 terminal No. 2 (Black/White wire). If resistance is 5 ohms or less, repair module communication concern. See MODULE COMMUNICATIONS NETWORK - MUSTANG article. If resistance is more than 5 ohms, repair open in Black/White wire between GEM and ground. Ground point is located behind center of instrument panel. See GROUND DISTRIBUTION article in WIRING DIAGRAMS.
Courtesy of FORD MOTOR CO.
Courtesy of FORD MOTOR CO.
Courtesy of FORD MOTOR CO.