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.

DTC Descriptors

DTC B2757: Driver Memory 1 Select Switch Circuit Low

DTC B2762: Driver Memory 2 Select Switch Circuit Low

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

B+, Memory Seat Adjuster Switch

B1420

1

--

--

Memory Seat Switch Signal 1

1

1

B2757

--

Memory Seat Switch Signal 2

1

1

B2762

--

1. Memory recall is inoperative

Circuit/System Description

Battery voltage through the TILT/TELE SW/MEM SEAT MOD 10A located in the body control module fuse block is supplied at all times to the memory seat adjuster switch. When the memory recall switches are pressed they send a 12-volt signal to the memory seat module (MSM) indicating the memory recall request. In response to this signal, the MSM commands the driver seat motors to move to the appropriate seat positions stored in memory.

Conditions for Running the DTC

    • DTC B1327 must not be present.
    • Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

    • If a memory switch continues to be active for 30 seconds after the last motor controlled by MSM reaches the end of its travel, the switch will be considered shorted and the MSM will set a switch DTC.
    • If a position sensor DTC is current and the associated switch is active for 30 continuous seconds, the switch will be considered shorted and the MSM will set a switch DTC.

Actions Taken When the DTC Sets

    • Current and history codes are set.
    • All memory recall commands and class 2 Driver Identifier are ignored.
    • The MSM will respond to any other switch signal that has not set a DTC.

Conditions for Clearing the DTCs

    • The DTC automatically clears when the switch circuit setting the DTC is no longer active.
    • A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.

Diagnostic Aids

The memory seat module is also referred to as the Driver Position Module in certain scan tool menus.

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

Ignition ON, observe the scan tool Driver Position Module memory seat switch parameters listed below while pressing and releasing the appropriate memory switch. The reading should change between Inactive and Active when the switch is pressed and released.

    • Memory 1 Select Switch
    • Memory 2 Select Switch

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the memory seat adjuster switch.
  2. Ignition On, verify the Driver Position Module memory seat switch parameters listed below are Inactive:
  3. • Memory 1 Select Switch
    • Memory 2 Select Switch
    If not the specified value, test the appropriate signal circuit listed below for a short to voltage. If the circuit tests normal, replace the MSM
    • Memory 1 switch signal terminal A
    • Memory 2 switch signal terminal B
  4. If all circuits test normal, replace the memory seat adjuster switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Driver Seat Adjuster Memory Switch Replacement
    •  Control Module References for MSM replacement, setup, and programming