Buick Regal: DTC B2755 or B2765

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 B2755

Seat Memory Select Switch Circuit

DTC B2765

Seat Memory Set Switch Circuit

For symptom byte information refer to Symptom Byte List.

Diagnostic Fault Information

1. Memory recall is inoperative

Circuit/System Description

Low reference is supplied to the seat memory switch from the seat memory control module. When a memory switch is pressed, the signal circuit from the seat memory control module is pulled low through the switch contacts and series of resistors indicating the memory recall request. In response to this signal, the seat memory control module commands the appropriate seat motors to move to the prerecorded seat positions stored in memory.

Conditions for Running the DTC

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

Conditions for Setting the DTC

B2755 01

If the seat memory control module detects a short to voltage on the memory seat switch signal circuit this DTC will set.

B2755 02

If the seat memory control module detects a short to ground on the memory seat switch signal circuit this DTC will set.

B2755 59

The seat memory control module detects a stuck Memory 1 or Memory 2 switch for a given amount of time.

B2765 59

If the memory set switch signal is active for greater than 15 s this DTC will set.

Actions Taken When the DTC Sets

• Current and history DTCs are set.
• All memory recall commands and are ignored.

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• The DTC automatically clears when the switch circuit setting the DTC is no longer active.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 fault-free ignition cycles have occurred.

Reference Information

Schematic Reference

• Driver Seat Wiring Schematics
• Passenger Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

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. Ignition ON.

2. Verify the appropriate scan tool Driver or Passenger Seat Memory Recall Switches parameter changes between Inactive and Memory 1 when pressing the memory 1 switch.

• If the parameter does not change

Refer to Circuit/System Testing.

• Go to next step: If the parameter changes

3. Verify the appropriate scan tool Driver or Passenger Seat Memory Recall Switches parameter changes between Inactive and Memory 2 when pressing the memory 2 switch.

• If the parameter does not change

Refer to Circuit/System Testing.

• Go to next step: If the parameter changes

4. Verify the appropriate scan tool Driver or Passenger Seat Memory Recall Switches parameter changes between Inactive and Exit when pressing the Exit switch.

• If the parameter does not change

Refer to Circuit/System Testing.

• Go to next step: If the parameter changes

5. Verify the appropriate scan tool Driver or Passenger Seat Memory Set Switch parameter changes between Inactive and Active when pressing the SET switch.

• If the parameter does not change

Refer to Circuit/System Testing.

• Go to next step: If the parameter changes

6. All OK.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate seat memory switch listed below, ignition ON.

• S47D Seat Memory Switch - Driver
• S47P Seat Memory Switch - Passenger

2. Press a power seat switch in order to wake up the K40 Seat Memory Control Module.

3. Test for 9 V or greater between each signal circuit terminal listed below and ground:

• Memory set switch signal terminal 5
• Memory switch signal terminal 6
• If less than 9 V

1. Ignition OFF, disconnect the X6 harness connector at the K40 Seat Memory Control Module.
2. Test for infinite resistance between the signal circuit and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • Go to next step: If infinite resistance
3. Test for less than 2 Ω in the signal circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, replace the K40 Seat Memory Control Module.

• Go to next step: If 9 V or greater

4. Ignition OFF, disconnect the X6 harness connector at the K40 Seat Memory Control Module, ignition ON.

5. Test for less than 1 V between each signal circuit terminal listed below and ground:

• Memory set switch signal terminal 5
• Memory switch signal terminal 6
• If 1 V or greater

Repair the short to voltage on the circuit.

• Go to next step: If less than 1 V

6. Test or replace the S47 Seat Memory Switch.

Component Testing

Seat Memory Switch

1. Ignition OFF, disconnect the harness connector at the S47 Seat Memory Switch.

2. Test for infinite resistance between each signal terminal listed below and the low reference terminal 1 with the switch in the open position.

• Terminal 5
• Terminal 6
• If less than infinite resistance

Replace the S47 Seat Memory Switch.

• Go to next step: If infinite resistance

3. Test for less than 4 Ω between the signal terminal 5 and the low reference terminal 1 while pressing the memory SET button.

• If 4 Ω or greater

Replace the S47 Seat Memory Switch.

• Go to next step: If less than 4 Ω

4. Test for 573 - 701 Ω between the signal terminal 6 and the low reference terminal 1 while pressing the memory 1 button.

• If not between 573 - 701 Ω

Replace the S47 Seat Memory Switch.

• Go to next step: If between 573 - 701 Ω

5. Test for 1800 - 2201 Ω between the signal terminal 6 and the low reference terminal 1 while pressing the memory 2 button.

• If not between 1800 - 2201 Ω

Replace the S47 Seat Memory Switch.

• Go to next step: If between 1800 - 2201 Ω

6. Test for 5.52k - 6.73 kΩ between the signal terminal 6 and the low reference terminal 1 while pressing the Exit button.

• If not between 5.52k - 6.73 kΩ

Replace the S47 Seat Memory Switch.

• Go to next step: If between 5.52k - 6.73 kΩ

7. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Front Seat Adjuster Memory Switch Replacement
• Control Module References for K40D Seat Memory Control Module - Driver or K40P Seat
• Memory Control Module - Passenger replacement, programming, and setup

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