Power Seats Diagnostic System Check

Turn ignition off. Connect scan tool to Data Link Connector (DLC). Turn ignition on. Attempt to establish communication with Memory Seat Module (MSM). If scan tool communicates with MSM, go to next step. If scan tool does not communicate with MSM, go to step 3 .
Display MSM DTCs using scan tool. If any DTCs are set in MSM, go to MEMORY SEAT MODULE DIAGNOSTIC TROUBLE CODES table. If no DTCs are set in MSM, go to MEMORY SEATS SYSTEM CHECK or LUMBAR SUPPORT MEMORY SYSTEM CHECK under TROUBLE SHOOTING.
Attempt to establish communications with other modules connected to class 2 serial data line (PCM, DIM, etc.). If scan tool communicates with other modules, go to next step. If scan tool does not communicate with other modules, go to SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SELF-DIAGNOSTIC SYSTEM in BODY CONTROL MODULES - ELDORADO article.
Using a test light connected to ground, probe BATT fuse (10-amp) located in rear compartment fuse block. If test light illuminates, go to next step. If test light does not illuminate, go to step 7 .
Turn ignition off. Disconnect MSM connectors. Turn ignition on. Using a test light connected to ground, probe MSM connector C2 terminal "D" (Orange wire) and C4 terminal "B" (Red wire). See Fig 1 . If test light illuminates at both terminals, go to next step. If test light does not illuminate at both terminals, go to step 9 .
Using a test light connected to battery voltage, probe MSM connector C2 terminal "C" (Black wire). If test light illuminates, go to step 8 . If test light does not illuminate, go to step 10 .
Repair open in battery feed to BATT fuse. See appropriate POWER DISTRIBUTION article in WIRING DIAGRAMS. If fuse is blown, locate and repair short to ground in Orange wire between rear compartment fuse block and MSM. After repairs, go to step 11 .
Replace MSM. See MEMORY SEAT MODULE under REMOVAL & INSTALLATION. After repairs, go to step 11 .
Repair open in Red wire between left underhood fuse block and MSM, or open in Orange wire between rear compartment fuse block and MSM. After repairs, go to step 11 .
Repair open in Black wire between MSM and ground G302 located under left front seat. After repairs, go to next step.
Turn ignition off. Reconnect any disconnected components or connectors. Turn ignition on. Using scan tool, clear all DTCs. After clearing DTCs, go to step 1 .