Buick Regal: DTC B1735, B1740, B1745, B1750, B1755, B1760, B1815, or B1820 (Driver Seat)
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 B1735
Seat Front Up Switch Circuit
DTC B1740
Seat Front Down Switch Circuit
DTC B1745
Seat Rear Up Switch Circuit
DTC B1750
Seat Rear Down Switch Circuit
DTC B1755
Seat Assembly Forward Switch Circuit
DTC B1760
Seat Assembly Rearward Switch Circuit
DTC B1815
Seat Recline Forward Switch Circuit
DTC B1820
Seat Recline Rearward Switch Circuit
For symptom byte information refer to Symptom Byte List.
Diagnostic Fault Information
1. Power seat is inoperative
Circuit/System Description
The seat memory control module supplies a reference voltage to each signal
circuit of the driver seat
adjuster switch. When the power seat switches are pressed, the appropriate
signal circuit from the seat
memory control module is pulled low through the switch contacts indicating the
power seat command.
The seat memory control module then commands the driver seat to move in response
to the switch
signals.
Conditions for Running the DTC
- DTC B1325 must not be present.
- Module battery voltage must be between 9 - 16 V.
Conditions for Setting the DTC
- If a seat or lumbar switch circuit is active in one direction and the
switch for the opposite direction
is pressed, this DTC will set.
- A short to ground on a switch signal circuit.
Action Taken When the DTC Sets
- A motor output driven in response to a switch considered failed, is
deactivated for both directions.
- All memory recall commands are ignored.
- The seat memory control module will respond to any other switch signal
that has not set a DTC.
Conditions for Clearing the DTC
- The current DTC will clear and set the DTC to history, when the fault is
no longer present and the
ignition is cycled OFF then back to ACC or RUN.
- The history DTC will clear after 40 consecutive fault-free ignition
cycles have occurred.
Diagnostic Aids
- If one of the switch signal circuits is shorted to ground, multiple DTCs
will set.
- If a switch is stuck in one direction and the switch is pressed in the
opposite direction, a single
DTC will set.
Reference Information
Schematic Reference
Driver 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 scan tool seat switch parameters listed below change between
Inactive and
Forward/Rearward or UP/Down when pressing the appropriate seat directional
switch.
- Driver Seat Cushion Front Vertical Switch
- Driver Seat Cushion Rear Vertical Switch
- Driver Seat Horizontal Switch
- Driver Seat Back Switch
- If the parameter does not change
Refer to Circuit/System Testing.
- Go to next step: If the parameter changes
3. All OK.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the S64D Seat Adjuster
Switch - Driver.
2. Clear present DTCs to enable system.
3. Verify that all scan tool driver seat switch parameters listed below are
Inactive:
- Driver Seat Cushion Front Vertical Switch
- Driver Seat Cushion Rear Vertical Switch
- Driver Seat Horizontal Switch
- Driver Seat Back Switch
- If not Inactive
- Ignition OFF, disconnect the X5 harness connector at the K40D Seat
Memory Control
Module - Driver, ignition ON.
- Test for infinite resistance between the appropriate signal circuit
terminal listed below and
ground:
- Front vertical up switch terminal A
- Front vertical down switch terminal K
- Rear vertical up switch terminal F
- Rear vertical down switch terminal J
- Horizontal forward switch terminal D
- Horizontal rearward switch terminal C
- Recline forward switch terminal H
- Recline rearward switch terminal G
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance, replace the K40D Seat Memory Control Module
- Driver.
- Go to next step: If Inactive
4. Install a 3 A fused jumper wire between the appropriate signal circuit
terminal listed below and
the ground circuit terminal E.
- Front vertical up switch terminal A
- Front vertical down switch terminal K
- Rear vertical up switch terminal F
- Rear vertical down switch terminal J
- Horizontal forward switch terminal D
- Horizontal rearward switch terminal C
- Recline forward switch terminal H
- Recline rearward switch terminal G
5. Verify the appropriate scan tool seat switch parameter is Forward/Rearward
or UP/Down.
- If not Forward/Rearward or UP/Down
- Ignition OFF, disconnect the X5 harness connector at the K40D Seat
Memory Control
Module - Driver, ignition ON.
- Test for less than 1 V between the signal circuit terminal and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- Go to next step: If less than 1 V
- Ignition OFF.
- 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 K40D Seat Memory Control Module -
Driver.
- Go to next step: If Forward/Rearward or UP/Down
6. Test or replace the S64D Seat Adjuster Switch - Driver.
Component Testing
Seat Adjuster Switch Test
1. Ignition OFF, disconnect the harness connector at the S64D Seat Adjuster
Switch - Driver.
2. Test for infinite resistance between the ground terminal E and each signal
terminal with the switch
in the open position.
- If less than infinite resistance
Replace the S64D Seat Adjuster Switch - Driver.
- Go to next step: If infinite resistance
3. Test for less than 2 Ω between the ground terminal E and each signal
terminal with the appropriate
switch in the closed position.
Replace the S64D Seat Adjuster Switch - Driver.
- Go to next step: If less than 2 Ω
4. All OK.
Repair Instructions
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
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
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 - 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 Descriptor
DT
SPECIFICATIONS
FASTENER SPECIFICATIONS
Reusable Threaded Fastener Tightening Specifications
NOTE:
All fasteners listed in this table can be reused after removal.
SCHEMATIC WIRING DIAGRAMS
SIR WIRING SCHEMATICS
Power, Ground, Serial Data, and Indicator
Passenger Presence System
Frontal Impact Sens