GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2005 🢒 Terraza - 4WD 🢒 Brakes 🢒 Park Brake 🢒 DTC B2755 or B2760

Circuit Description

When the memory recall switches are pressed they send a 12-volt signal to the memory seat module (MSM). The MSM then commands the driver seat to move in response to the switch inputs.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

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

Conditions for Running the DTC

The MSM must be powered and cannot have B1327 - Battery Voltage Low as an active DTC for this DTC to set.

Conditions for Setting the DTC
    • If a memory switch continues to be active for 30 seconds after the last motor controlled by MSM/driver position module (DPM) 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.

Action 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 DTC
    • The DTC automatically clears when the switch circuit setting the DTC is no longer active.
    • The MSM will clear the history DTC after 50 fault-free ignition cycles.

Test Description

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

  1. This step checks the existing state of the memory switch by using the current state of the switch parameter.

    2.

  2. This step verifies the repair.

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 in Vehicle DTC Information

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the appropriate memory switch parameter.

Does the scan tool display Inactive?

Go to Step 3

Go to Step 4

3
  1. With a scan tool, observe the appropriate memory switch parameter.
  2. Activate the appropriate memory switch.

Does the switch parameter change state?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 4

4
  1. Turn OFF the ignition.
  2. Disconnect the memory function switch harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the appropriate switch parameter.

Does the scan tool display Inactive for the switch parameter?

Go to Step 7

Go to Step 5

5

Test the switch signal circuit that displays active for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 6

6

Inspect for poor connections at the harness connector of the memory seat module (MSM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 8

7

Inspect for poor connections at the harness connector of the memory function switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 9

8

Replace the MSM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 10

--

9

Replace the memory function switch.

Did you complete the replacement?

Go to Step 10

--

10

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK