Test B: No Communication With Rear Electronic Module
WARNING: This page is about a different car, the 2001 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Ignition switch must be cycled from LOCK to RUN position to enable Switched System Power (SSP) feature. Always enable SSP feature before proceeding with test procedures.
- Turn ignition switch to LOCK position. Disconnect Rear Electronic Module (REM) 26-pin harness connector 420c. Disconnect REM 20-pin harness connector C420d. REM is located on right side of luggage compartment, above battery. See Fig 1 . Turn ignition switch to RUN position. Measure voltage between ground and REM harness connector C420d terminal No. 3 (Orange/Black wire). See Fig 2 . Measure voltage between ground and REM harness connector 420c terminal No. 13 (Orange/Black wire). If battery voltage exists at both terminals, go to next step. If battery voltage does not exist at either terminal, repair power distribution circuit as necessary. See POWER DISTRIBUTION article in WIRING DIAGRAMS.
- Turn ignition switch to LOCK position. Disconnect remaining REM harness connectors. Measure resistance between ground and appropriate REM harness connector terminal. See REAR ELECTRONIC MODULE TERMINAL IDENTIFICATION
table. See Fig 2
. If all resistances are less than 5 ohms, repair module communications concern. See MODULE COMMUNICATIONS NETWORK - LS article. If any resistance is 5 ohms or more, repair open in appropriate wire between ground and REM. See GROUND DISTRIBUTION article in WIRING DIAGRAMS.REAR ELECTRONIC MODULE TERMINAL IDENTIFICATION
Connector Terminal No. Wire Color C420b 12 Black/Orange 420c 11, 12, 25 & 26 Black/Orange C420d 2 Black/Orange C420f 3 Black/Orange