Reference voltage from the seat interface module (SIM) is supplied at all times to the memory seat switch. When a memory recall switch is pressed, reference voltage is applied through the switch contacts and the signal circuit to the SIM indicating the memory recall request. The SIM serves as a interface and applies a reference voltage through the appropriate memory signal circuit to the memory seat module (MSM) indicating the memory seat request. The MSM then commands the driver seat motors and the exterior mirrors to move to the appropriate seat and mirror positions stored in memory.

Schematic Reference

Driver Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

1. Verify that all manual power seat and lumbar functions operate when being controlled by the seat adjuster and lumbar switches.

⇒	If any seat or lumbar function does not operate, refer to Power Seat Inoperative or Lumbar Support Inoperative.

2. Ignition ON, observe the scan tool SIM Input parameters listed below while pressing the appropriate memory 1, 2, and 3 switches. The readings should change between Inactive and Active.

•	Button 1 Input Status

•	Button 2 Input Status

•	Button 3 Input Status

⇒	If not the specified value for all memory buttons, refer to the Memory Seat Switch Circuit Test.

3. Ignition ON, observe the scan tool MSM Input parameters listed below while pressing the appropriate memory 1, 2, and 3 switches. The readings should change between Not Pressed and Pressed.

•	Memory 1 Button

•	Memory 2 Button

•	Memory 3 Button

⇒	If not the specified value for all memory buttons, refer to the SIM to MSM Circuit Test.

4. If all scan tool readings are normal, replace the MSM.

Memory Seat Switch Circuit Test

1. Ignition OFF, disconnect the harness connector at the memory seat switch.
2. Ignition ON, verify that a test lamp illuminates between the 12 V reference circuit terminal 6 and ground.

⇒	If the test lamp does not illuminate, test the 12 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the SIM.

3. Ignition ON, verify the scan tool SIM Input parameters listed below are Inactive:

•	Button 1 Input Status

•	Button 2 Input Status

•	Button 3 Input Status

•	Button M Input Status

⇒	If not the specified value, test the appropriate signal circuit for a short to voltage. If the circuit tests normal, replace the SIM.

4. Install a 3 A fused jumper wire between the 12 V reference circuit terminal 6 and the signal circuit terminals listed below. Verify the appropriate scan tool SIM Memory Button Input Status parameter is Active between each test.

•	Button 1 Input Status

•	Button 2 Input Status

•	Button 3 Input Status

•	Button M Input Status

⇒	If not the specified value, test the appropriate signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the SIM.

5. If all circuits test normal, test or replace the memory seat switch.

SIM to MSM Circuit Test

1. Ignition OFF, disconnect the X3 harness connector at the MSM.
2. Connect a test lamp between the appropriate signal circuit listed below and ground:

•	Memory 1 terminal 9

•	Memory 2 terminal 8

•	Memory 3 terminal 19

•	Memory M terminal 18

3. Ignition ON, command the appropriate memory position listed below ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

•	Button 1 Input

•	Button 2 Input

•	Button 3 Input

•	Button M Input

⇒	If the test lamp is always ON, test the signal circuit for a short to voltage. If the circuit tests normal replace the SIM.

⇒	If the test lamp is always OFF, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal replace the SIM.

4. If all circuits test normal, replace the MSM.

1. Ignition OFF, disconnect the harness connector at the memory seat switch.
2. Test for infinite resistance between the 12 V reference terminal 6 and each signal terminal listed below with the switch in the open position:

•	Memory 1 terminal 1

•	Memory 2 terminal 2

•	Memory 3 terminal 3

•	Memory M terminal 4

⇒	If not the specified value, replace the memory seat switch.

3. Test for less than 2 Ω between the 12 V reference terminal 6 and each signal terminal listed below with the appropriate switch in the closed position:

•	Memory 1 terminal 1

•	Memory 2 terminal 2

•	Memory 3 terminal 3

•	Memory M terminal 4

⇒	If greater than the specified range, replace the memory seat switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.