GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Memory Switch Reference Voltage

--

1

--

--

Memory Switch Signal

1

1

1

--

1. Memory seat feature inoperative

Circuit/System Description

Reference voltage is supplied to the memory switch from the driver door lock/window switch. When a memory switch is pressed, reference voltage is applied through the switch contacts, a series of resistors and thorough the memory switch signal circuit to the door lock/window switch. The door lock/window switch then sends a serial data message to the memory seat module (MSM) indicating the memory recall request. The MSM then commands the appropriate seat motors to move to the pre-recorded seat positions stored in memory in response to the switch input.

Reference Information

Schematic Reference

Driver Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Power Seats System Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Verify that all manual power seat and lumbar functions operate when being controlled by the seat adjuster and lumbar switches.
  2. If any seat function does not operate, refer to Power Seat Inoperative or Lumbar Support Inoperative.
  3. Verify that the memory recall personalization option is ON. Refer to the owners manual.
  4. Verify that memory positions for driver 1 and driver 2 have been recorded to memory by observing the scan tool Driver Position Module, Memory Data 1 and Memory Data 2 parameters.

Circuit/System Testing

  1. Ignition ON, verify the scan tool Driver Door Switch Memory Recall Switches parameter is approximately 2.75 V while pressing the memory 1 switch.
  2. If not the specified value, refer to the Memory Switch component test. If the switch tests normal, replace the driver door lock/window switch.
  3. Verify the scan tool Memory Recall Switches parameter is approximately 1.75 V while pressing the memory 2 switch.
  4. If not the specified value, test or replace the memory switch.
  5. Verify the scan tool Memory Recall Switches parameter is approximately 1.0 V while pressing the EXIT switch.
  6. If not the specified value, test or replace the memory switch.
  7. If all circuits test normal, replace the memory seat module.

Component Testing

Memory Switch

  1. Disconnect the X4 harness connector at the door lock/window switch.
  2. Test for infinite resistance between the signal circuit terminal 5 and the 12 V reference circuit terminal 14 with the switch in the open position.
  3. If not the specified value, replace the memory switch.
  4. Test the resistance between terminal 5 and terminal 14 while pressing the memory 1, memory 2, and EXIT buttons. Compare the resistance readings to the values in the Memory Switch Values table below.
  5. If the resistance is not within the specified range, replace the memory switch.

Memory Switch Values

Switch Position

Resistance

Idle

Infinite

Memory 1

2.03 k - 2.49 kΩ

Memory 2

3.83 k - 4.69 kΩ

Exit

9.32 k- 10.18 kΩ

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Driver Seat Adjuster Memory Switch Replacement
    •  Control Module References for MSM or door lock/window switch replacement, programming, and setup