Test Aa: No Communication With Remote Emergency Satellite Cellular Unit

1. Turn ignition switch to LOCK position. Disconnect Remote Emergency Satellite Cellular Unit (RESCU) harness connector C401a. Turn ignition switch to RUN position. Measure voltage at terminals No. 1 (Red/Black wire) and No. 7 (Pink/Orange wire) at RESCU harness connector C401a. See Fig 1 . If battery voltage exists at both terminals, go to next step. If battery voltage does not exist at either terminal, repair power distribution circuit(s) as necessary. See POWER DISTRIBUTION article in WIRING DIAGRAMS.
2. Turn ignition switch to LOCK position. Measure resistance between ground and terminal No. 6 (Black/Red wire) at RESCU harness connector C401a. If resistance is 5 ohms or less, repair module communications concern. See MODULE COMMUNICATIONS NETWORK - LS . If resistance is greater than 5 ohms, repair open in Black/Red wire between RESCU and ground.

Fig 1: Identifying Remote Emergency Satellite Cellular Unit Module Harness Connector Terminals

Courtesy of FORD MOTOR CO.