Buick Regal: DTC B392B
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 B392B 00
Seat Lumbar/Bolster Pump
Diagnostic Fault Information
1. The lumbar, bolster and massage functions are inoperative
Circuit/System Description
When a seat lumbar, bolster, or massage function is commanded ON, the seat
bolster memory control
module applies battery voltage and a low side drive pulse width modulated (PWM)
signal through their
respective control circuits to the seat lumbar/bolster pump. The logic in the
pump interprets this signal
and pump runs to inflate the lumbar/bolster bladders until the switch is
released.
Conditions for Running the DTC
- Ignition ON.
- The voltage control circuit to the lumbar/bolster pump must be active.
Conditions for Setting the DTC
The seat bolster memory control module detects a short to ground on the
lumbar/bolster pump voltage
control circuit.
Action Taken When the DTC Sets
All lumbar, bolster, and massage functions are inoperative.
Conditions for Clearing the DTC
- The DTC clears when the diagnostic runs and passes.
- The history DTC will clear after 40 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
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 Testing
1. Ignition OFF, all vehicle systems OFF, disconnect the harness connector at
the appropriate seat
lumbar/bolster pump listed below:
- G31D Seat Lumbar/Bolster Pump - Driver
- G31P Seat Lumbar/Bolster Pump - Passenger
2. Test for less than 10 Ω between the low reference circuit terminal 2 and
ground.
- Ignition OFF.
- 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
3. Connect a test lamp between the control circuit terminal 1 and ground,
ignition ON.
4. Verify the test lamp turns ON after pressing and holding the lumbar forward
switch.
- If the test lamp remains OFF
- Ignition OFF, remove the test lamp, disconnect the harness connector at
the K134 Seat
Bolster Memory Control Module.
- 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
- 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.
- Go to next step: If the test lamp turns ON
5. Test or replace the G31 Seat Lumbar/Bolster Pump.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Front Seat Back Lumbar Replacement (2 Way) or Front Seat Back Lumbar
Replacement
(GS) or Front Seat Back Lumbar Replacement (4 Way)
- Control Module References for K134D Seat Bolster Memory Control Module -
Driver or K134P
Seat Bolster Memory Control Module - Passenger replacement, programming and
setup
READ NEXT:
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.
Diag
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 follo
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.
Diag
SEE MORE:
Diagnostic Instructions
Perform the Diagnostic System Check prior to using this diagnostic
procedure: Diagnostic
System Check - Vehicle
Review the description of Strategy Based Diagnosis: Strategy Based
Diagnosis
An overview of each diagnostic category can be found here: Diagnostic
Proced
Removal Procedure
WARNING: Brake Dust Warning
1. Set the park brake in Service Mode.
Manual Method
Change the transmission gear to neutral or park position.
Press and hold the push button start switch for 10 seconds, with the
brake pedal not applied.
This will place the vehicle in Service Mode