Test B: No Communication With Rear Electronics Module
NOTE:
Cycle ignition switch from LOCK to RUN position to enable the switched system power feature.
NOTE:
After any repairs are complete, ensure all component are properly installed and all harness connectors are connected properly and repeat data link diagnostic test. See DATA LINK DIAGNOSTIC TEST under SELF-DIAGNOSTIC SYSTEM in appropriate MODULE COMMUNICATIONS NETWORK - LS article.
- Turn ignition switch to LOCK position. Disconnect Rear Electronic Module (REM) 26-pin harness connectors C420c. Disconnect REM 20-pin harness connector C420c. REM is located in right side of trunk compartment, above battery. Turn ignition switch to RUN position. Measure voltage between ground and REM harness connector C420d terminal No. 3 (Orange/Black wire). See Fig 1 . Measure voltage between ground and REM harness connector C420c terminal No. 13 (Orange/Black wire). If battery voltage exists at both terminals, go to next step. If battery voltage does not exist at both terminals, 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 REM harness connector C420b terminal No. 12 (Black/Orange wire). Measure resistance between ground and REM harness connector C420c terminals No. 11, 12, 25 and 26 (all Black/Orange wires). Measure resistance between ground and REM harness connector C420d terminal No. 2 (Black/Orange wire). Measure resistance between ground and REM harness connector C420f terminal No. 3 (Black/Orange wire). Measure resistance between ground and REM harness connector C420g terminal No. 1 (Black/Orange wire). 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 REM and ground.