Buick Regal: Symptoms - Power Seats

NOTE: The following steps must be completed before using the symptom tables.

1. Perform the Diagnostic System Check - Vehicle before using the Symptom Tables in order to verify that all of the following are true:

• There are no DTCs set.
• The control modules can communicate via the serial data link.

2. Review the system operation in order to familiarize yourself with the system functions. Refer to the following system descriptions:

• Lumbar Support Description and Operation (With Memory Seat A44/A45) or Lumbar Support Description and Operation (Without Memory Seat A44/A45)
• Memory Seats Description and Operation
• Power Seats System Description and Operation

Visual/Physical Inspection

• Inspect for aftermarket devices which could affect the operation of the system. Refer to Checking Aftermarket Accessories.
• Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

• Lumbar/Bolster/Massage Malfunction (AVK with AF6 or AVU with AKE), Lumbar/Bolster/Massage Malfunction (AVK without AF6 or AVU without AKE), or Lumbar/Bolster/Massage Malfunction (AL9 or AT9)
• Memory Seat Feature Malfunction
• Power Seat Malfunction (Driver or Passenger without Memory A44 or A45), Power Seat Malfunction (Driver Seat with Memory A45), or Power Seat Malfunction (Passenger Seat with Memory A44)
• Power Folding Seat Malfunction

Lumbar/Bolster/Massage Malfunction (AVK with AF6 or AVU with AKE)

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

1. The lumbar, bolster, and massage functions are inoperative

Circuit/System Description

Ground is supplied to the driver and passenger seat lumbar support and the seat back side bolster switches. Each switch is also supplied with a 5 V reference and signal circuits from the seat memory control module. The reference voltage is applied to a resistive network internal to the switches. When a switch is pressed, the output of the resistive network results in a voltage drop on the signal circuit to the seat memory control module indicating the lumbar, bolster, or massage request. In response to this signal, the seat memory control module sends a LIN serial data message to the seat massage valve assembly commanding it to perform the required pneumatic movements.

The seat massage valve assembly contains the electronic circuitry for executing the commanded pneumatic seat adjustments, air direction solenoids, pressure sensors for storing air bladder pressures, and outputs which supplies battery power and a low side drive pulse width modulated (PWM) signal to the external seat air pump motor when any of the air bladders require inflating.

Reference Information

Schematic Reference

• Driver Seat Wiring Schematics
• Passenger Seat Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Lumbar Support Description and Operation (With Memory Seat A44/A45) or Lumbar Support Description and Operation (Without Memory Seat A44/A45)

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 Lumbar Support Horizontal Switch parameter changes between Inactive and Forward/Rearward when pressing the lumbar horizontal switch in the Forward and Rearward directions.

• If the parameter does not change in either direction

Refer to DTC B183B or B183C.

• Go to next step: If the parameter changes for both directions

3. Verify the scan tool Lumbar Support Vertical Switch parameter changes between Inactive and Up/Down when pressing the lumbar vertical switch in the Up and Down directions.

• If the parameter does not change

Test or replace the S65 Seat Lumbar Support Switch.

• Go to next step: If the parameter changes

4. Verify the scan tool Seat Back Side Bolster Switch parameter changes between Inactive and Inflate/Deflate when pressing the bolster switch in both directions.

• If the parameter does not change

Refer to DTC B183B or B183C.

• Go to next step: If the parameter changes

5. Verify the scan tool Seat Massage Switch parameter changes between Inactive and Active when pressing the seat massage switch.

• If the parameter does not change

Test or replace the S66 Seat Back Side Bolster Adjuster Switch.

• Go to next step: If the parameter changes

6. Refer to Circuit/System Testing.

Circuit/System Testing

1. Ignition OFF, all vehicle systems OFF, disconnect the harness connector at the appropriate seat bolster memory control module listed below. It may take up to 2 min for all vehicle systems to power down.

• K134D Seat Bolster Memory Control Module - Driver
• K134P Seat Bolster Memory Control Module - Passenger

2. Test for less than 10 Ω between the ground circuit terminal 3 and ground.

• If 10 Ω or greater

1. Ignition OFF.
2. Test for less than 2 Ω in the ground circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit
   • If less than 2 Ω, repair the open/high resistance in the ground connection.

• Go to next step: If less than 10 Ω

3. Ignition ON.

4. Verify a test lamp illuminates between the B+ circuit terminal 1 and ground.

• If the test lamp does not illuminate

1. Ignition OFF, remove the test lamp.
2. Test for infinite resistance between the B+ 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 B+ circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.

• Go to next step: If the test lamp illuminates

5. Ignition OFF, connect the harness connector at the K134 Seat Bolster Memory Control Module and disconnect the harness connector at the G31 Seat Lumbar/Bolster Pump.

6. Test for less than 10 Ω between the low reference circuit terminal 2 and ground.

• If 10 Ω or greater

1. Ignition OFF.
2. Test for less than 2 Ω in the low reference circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit
   • If less than 2 Ω, replace the K134 Seat Bolster Memory Control Module.

• Go to next step: If less than 10 Ω

7. Connect a test lamp between the control circuit terminal 1 and ground, ignition ON.

8. Verify the test lamp turns ON when pressing the lumbar forward switch.

• If the test lamp remains OFF

1. Ignition OFF, remove the teat lamp, disconnect the harness connector at the K134 Seat Bolster Memory Control Module.
2. Test for infinite resistance between the control 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 control circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit
   • If less than 2 Ω, replace the K134 Seat Bolster Memory Control Module.

• If the test lamp remains ON

1. Ignition OFF, remove the teat lamp, disconnect the harness connector at the K134 Seat Bolster Memory Control Module, ignition ON.
2. Test for less than 1 V between the control circuit and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • If less than 1 V, replace the K134 Seat Bolster Memory Control Module.

• Go to next step: If the test lamp turns ON and OFF

9. Test or replace the G31 Seat Lumbar/Bolster Pump.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Driver or Passenger Seat Lumbar Control Switch Replacement
• Front Seat Back Lumbar Replacement (2 Way) or Front Seat Back Lumbar Replacement (GS) or Front Seat Back Lumbar Replacement (4 Way)

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