Power Seat Does Not Move Forward/Rearward

NOTE: This procedure applies to vehicles equipped with memory systems only (A45). For option code definition, see REGULAR PRODUCTION OPTION CODES under DESCRIPTION.

If power seats diagnostic system check was performed, go to next step. If power seats diagnostic system check was not performed, go to POWER SEATS DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC TESTS.
Connect scan tool to Data Link Connector (DLC). See Figure . Turn ignition on. Using scan tool, select MEMORY SEAT MODULE data list. Monitor SEAT FORWARD parameter. Operate entire seat horizontal switch in forward direction. If SEAT FORWARD parameter changes, go to next step. If SEAT FORWARD parameter does not change, go to step 5 .
Monitor SEAT BACKWARD parameter. Operate entire seat horizontal switch in backward direction. If SEAT BACKWARD parameter changes, go to next step. If SEAT BACKWARD parameter does not change, go to step 6 .
Disconnect seat horizontal motor connector. See Figure . Connect a test light between horizontal motor connector terminals "A" (Tan wire) and "B" (Light Green wire). Operate entire seat horizontal switch in forward and backward directions. If test light does not illuminate in both directions, go to step 7 . If test light illuminates in both directions, go to step 13 .
Disconnect driver's power seat switch connector. Connect a 3-amp fused jumper wire between power seat switch connector terminal "E" (Tan wire) and "J" (Orange wire). See Figure . Monitor SEAT FORWARD parameter. If SEAT FORWARD parameter does not change, go to step 9 . If SEAT FORWARD parameter changes, go to step 12 .
Disconnect driver's power seat switch connector. Connect a 3-amp fused jumper wire between power seat switch connector terminal "B" (Light Green wire) and "J" (Orange wire). See Figure . Monitor SEAT BACKWARD parameter. If SEAT BACKWARD parameter does not change, go to step 10 . If SEAT BACKWARD parameter changes, go to step 12 .
Check for open or short to ground in Tan wire between Memory Seat Module (MSM) connector C3 terminal "N" and horizontal motor connector "A". See Figure . If circuit is okay, go to next step. If faulty circuit is found and repaired, go to step 17 .
Check for open or short to ground in Light Green wire between MSM connector C3 terminal "S" and horizontal motor connector "B". If circuit is okay, go to step 11 . If faulty circuit is found and repaired, go to step 17 .
Check for open or short to ground in Tan wire between Memory Seat Module (MSM) connector C2 terminal A5 (AC9) or E5 (AL2 or AM3) and power seat switch connector terminal "E". See Figure . If circuit is okay, go to step 11 . If faulty circuit is found and repaired, go to step 17 .
Check for open or short to ground in Light Green wire between Memory Seat Module (MSM) connector C2 terminal A6 (AC9) or E6 (AL2 or AM3) and power seat switch connector terminal "B". See Figure . If circuit is okay, go to next step. If faulty circuit is found and repaired, go to step 17 .
Check for poor connections at MSM connector. If connections are okay, go to step 14 . If faulty connections are found and repaired, go to step 17 .
Check for poor connections at driver's power seat switch connector. If connections are okay, go to step 15 . If faulty connections are found and repaired, go to step 17 .
Check for poor connections at horizontal motor connector. If connections are okay, go to step 16 . If faulty connections are found and repaired, go to step 17 .
Replace MSM. See MEMORY SEAT MODULE under REMOVAL & INSTALLATION. After repairs, go to step 17 .
Replace power seat switch. See DRIVER'S POWER SEAT SWITCH under REMOVAL & INSTALLATION. After repairs, go to step 17 .
Replace seat horizontal motor. See SEAT MOTORS under REMOVAL & INSTALLATION in POWER SEATS - DEVILLE article. After repairs, go to next step.
Recheck driver's power seat operation. If power seat malfunction is still present, go to step 2 . If power seat malfunction is no longer present, repair is complete.