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

Reference Voltage

1

1

--

--

Memory 1 Switch Signal

2

2

1

--

Memory 2 Switch Signal

3

3

1

--

1. All memory switch functions inoperative

2. Memory 1 and Exit functions inoperative

3. Memory 2 and Exit functions inoperative

Circuit/System Description

Reference voltage is supplied to the memory seat switch from the driver door lock/window switch. When the memory 1 or memory 2 switch is pressed, reference voltage is applied through the switch contacts and the appropriate 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. When the memory Exit switch is pressed, reference voltage is applied through both, the memory 1 and memory 2 switch signal circuits to the door lock/window switch. The door lock/window switch then sends a serial data message to the MSM indicating the memory Exit request. The MSM then commands the appropriate seat motors to move to the pre-recorded seat exit positions stored in memory.

Reference Information

Schematic Reference

Driver Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Memory Seats 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 the power seat operates in all directions from the seat adjuster switch.
  2. If the power seat does not operate normal, refer to Power Seat Inoperative.
  3. Ignition ON, observe the scan tool Driver Door Module Memory Switch parameter while activating the memory 1, memory 2, and exit switch functions. The reading should change between Idle and the active switch function.
  4. If not the specified value, refer to Memory Seat Adjuster Switch Component Test.
  5. If the memory seat switch tests normal, replace the driver door lock/window switch.
  6. If the memory switch inputs to the door lock/window switch function normal, replace the MSM.

Component Testing

Memory Seat Adjuster Switch Component Test

  1. Ignition OFF, disconnect the X4 harness connector at the driver door lock/window switch.
  2. Test for infinite resistance between the B+ terminal 5 and the signal terminals listed below with the switch in the open position.
  3. • Memory 1 signal terminal 6
    • Memory 2 signal terminal 7
    If not the specified value, replace the memory seat switch.
  4. Test for less than 1 Ω between the B+ terminal 5 and the signal terminals listed below with the appropriate switch in the closed position.
  5. • Memory 1 signal terminal 6
    • Memory 2 signal terminal 7
    If greater than the specified range, replace the memory seat switch.
  6. Test for less than 1 Ω between the signal terminal 6 and the B+ terminal 5 with the Exit switch in the closed position.
  7. If greater than the specified range, replace the memory seat switch.
  8. Test for less than 1 Ω between the signal terminal 7 and the B+ terminal 5 with the Exit switch in the closed position.
  9. If greater than the specified range, replace the memory seat switch.
  10. If the memory seat switch tests normal, replace the driver door lock/window switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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