Test A: No Communication With Rap Module
- Turn ignition switch to LOCK position. Check fuse No. 20 (7.5-amp) in Central Junction Box (CJB) and fuse No. 9 (20-amp) in Battery Junction Box (BJB). If fuses are okay, go to next step. Replace fuse(s) if necessary. If fuse(s) fail again, check for short in Black/Pink, Light Blue/Orange or White/Blue wire(s). Recheck system operation.
- Disconnect RAP module Gray 22-pin harness connector C338. Measure voltage between ground and RAP module harness connector C338 terminal No. 12 (White/Light Blue wire). See Fig 1. If more than 10 volts exist, go to next step. If 10 volts or less exist, repair open in White/Light Blue wire between BJB and RAP module. Recheck system operation.
- Disconnect RAP module Black 26-pin harness connector C336. Turn ignition switch to RUN position. Measure voltage between ground and RAP module harness connector C336 terminal No. 25 (Black/Pink wire). See Fig 2. If more than 10 volts exist, go to next step. If 10 volts or less exist, repair open in Black/Pink wire between CJB and RAP module. Recheck system operation.
- Turn ignition switch to LOCK position. Measure resistance between ground and RAP module harness connector C338 terminal No. 14 (Black/White wire). If resistance is less than 5 ohms, diagnose network concern. See MODULE COMMUNICATIONS NETWORK - EXPLORER & MOUNTAINEER article. If resistance is 5 ohms or more, repair open in Black/White wire between RAP module and ground. Ground point is located in left front of engine compartment, near radiator. Recheck system operation.
Courtesy of FORD MOTOR CO.
Courtesy of FORD MOTOR CO.