Driver Seat Front Riser Movement Inoperative

1. Using DVOM, select BODY, MEMORY SEAT MODULE then ACTUATORS. Actuate FRONT RISER MOTOR up and down using scan tool. If front of driver's seat moves up and down, go to next step. If front of driver's seat does not move up and down, go to step  6.
2. Turn ignition off. Disconnect Memory Seat Module (MSM) connector C1. See Figure. MSM is located under driver's seat. Disconnect driver's power seat switch connector. Using DVOM, measure resistance of Red/Light Green wire between driver's power seat switch connector terminal No. 10 and MSM connector C1 terminal No. 14. See Figure and Fig 1 . If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, repair open in Red/Light Green wire. Perform MEMORY/HEATED SEATS VERIFICATION TEST  under VERIFICATION TESTS.
3. Using DVOM, measure resistance of Yellow/Light Green wire between driver's power seat switch connector terminal No. 7 and MSM connector C1 terminal No. 5. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, repair open in Yellow/Light Green wire. Perform MEMORY/HEATED SEATS VERIFICATION TEST  under VERIFICATION TESTS.
4. Reconnect driver's power seat switch connector. Connect test light between MSM connector C1 terminals No. 5 (Yellow/Light Green wire) and No. 14 (Red/Light Green wire). Move front of seat up and down using switch. If test light illuminates when switch is operated in both directions, go to next step. If test light does not illuminate when switch is operated in both directions, replace driver's power seat switch. Perform MEMORY/HEATED SEATS VERIFICATION TEST  under VERIFICATION TESTS.
5. Replace MSM. See MEMORY HEATED SEAT MODULE, HEATED SEAT MODULE, MEMORY SEAT MODULE  under REMOVAL & INSTALLATION. Perform MEMORY/HEATED SEATS VERIFICATION TEST  under VERIFICATION TESTS.
6. Turn ignition off. Disconnect Memory Seat Module (MSM) connector C2. See Figure. MSM is located under driver's seat. Disconnect driver's power seat front riser motor 2-pin connector. Using DVOM, measure resistance of Red/Gray wire between MSM connector C2 terminal No. 5 and driver's power seat front riser motor connector terminal No. 2. See Figure. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, repair open in Red/Gray wire. Perform MEMORY/HEATED SEATS VERIFICATION TEST  under VERIFICATION TESTS.
7. Using DVOM, measure resistance of Yellow/Red wire between MSM connector C2 terminal No. 4 and driver's power seat front riser motor connector terminal No. 1. See Figure. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, repair open in Yellow/Red wire. Perform MEMORY/HEATED SEATS VERIFICATION TEST  under VERIFICATION TESTS.
8. Reconnect driver's power seat front riser motor 2-pin connector. Connect a fused jumper between MSM connector C2 terminals No. 5 (Red/Gray wire) and No. 12 (Black wire). Connect a second fused jumper between MSM connector C2 terminals No. 4 (Yellow/Red wire) and momentarily to No. 1 (Red wire). Switch jumper wires between MSM connector C2 terminals No. 12 (Black wire) and No. 1 (Red wire). If front of seat moves up and down when fused jumpers are connected, go to next step. If front of seat does not move up and down when fused jumpers are connected, replace seat track assembly. See appropriate POWER SEATS article. Perform MEMORY/HEATED SEATS VERIFICATION TEST  under VERIFICATION TESTS.
9. Replace MSM. See MEMORY HEATED SEAT MODULE, HEATED SEAT MODULE, MEMORY SEAT MODULE  under REMOVAL & INSTALLATION. Perform MEMORY/HEATED SEATS VERIFICATION TEST  under VERIFICATION TESTS.

Fig 1: Identifying Driver's Power Seat Switch Connector Terminals

Courtesy of DAIMLERCHRYSLER CORP.