GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The memory select switch signal circuits are supplied 12 volts through a resistor and monitored within the memory seat module (MSM). When a memory select switch is pressed, the signal circuit is closed to ground and the signal circuit voltage is pulled low.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC B2755 Memory 1 Select Switch Circuit
    • DTC B2760 Memory 2 Select Switch Circuit

Conditions for Running the DTC

The system voltage must be between 9-16 volts.

Conditions for Setting the DTC

A memory select switch input to the memory seat module is active for more than 30 seconds.

Action Taken When the DTC Sets

    • The MSM will ignore the switch input for which a current status DTC is set.
    • When the fault is no longer present a history status DTC will be stored, and switch operation will be restored.

Conditions for Clearing the DTC

    • The DTC will be current for as long as the fault is present.
    • When the fault is no longer present the DTC will be a history status code.
    • The history DTC will be cleared after 100  error free ignition cycles, or by using the scan tool clearing DTCs feature.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Verify that the DTC is current or history by monitoring the switch status for which the code is set.

  2. Tests the memory select switch for an internal fault.

Step

Action

Yes

No

Schematic Reference: Driver Seat Schematics

Connector End View Reference: Power Seat Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. With a scan tool, observe the Memory Select Switch parameter in the memory seat module (MSM) data list.

Does the scan tool display inactive?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Disconnect the memory select switch connector.
  2. With a scan tool, observe the Memory Select Switch parameter.

Does the scan tool display inactive?

Go to Step 5

Go to Step 4

4

Test the switch signal circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 9

Go to Step 6

5

Inspect and repair any damage to the memory select switch connector and terminals which may cause the condition. Refer to Circuit Testing and to Wiring Repairs.

Did you find and correct the condition?

Go to Step 9

Go to Step 7

6

Inspect and repair any damage to the MSM connector and terminals which may cause the condition. Refer to Circuit Testing and to Wiring Repairs.

Did you find and correct the condition?

Go to Step 9

Go to Step 8

7

Replace the memory select switch. Refer to Driver Seat Adjuster Memory Switch Replacement .

Did you complete the replacement?

Go to Step 9

--

8

Replace the MSM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 9

--

9

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the system in order to verify the repair.

Does the DTC reset?

Go to Step 2

System OK