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.