Power Seat System Buick Encore I

Scheme 44

Scheme 45

Scheme 46

Scheme 47

Scheme 48

Diagnostic Code Index

DIAGNOSTIC CODE INDEX

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

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

1. DTC B1325 must not be present.
2. Module battery voltage must be between 9-16 V.

Conditions for Setting the DTC

1. If a seat switch circuit is active in one direction and the switch for the opposite direction is pressed, this DTC will set.
2. A short to ground on a switch signal circuit.

Action Taken When the DTC Sets

1. A motor output driven in response to a switch considered failed, is deactivated for both directions.
2. All memory recall commands are ignored.
3. The seat memory control module will respond to any other switch signal that has not set a DTC.

Conditions for Clearing the DTC

1. The current DTC will clear and set the code to history, when the fault is no longer present and the ignition is cycled OFF then back to ACC or RUN.
2. The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.

Diagnostic Aids

1. If one of the switch signal circuits is shorted to ground, multiple codes will set.
2. If a switch is stuck in one direction and the switch is pressed in the opposite direction, a single code will set.

Reference Information

Schematic Reference

Driver Seat Schematics (Encore) , Driver Seat Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__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 If the parameter does not change Refer to Circuit/System Testing. If the parameter changes
3. All OK.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the S64D Seat Adjuster Switch - Driver, Ignition ON.
2. 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 If not Inactive Ignition OFF, disconnect the harness connector at the K40 Seat Memory Control Module. Test for infinite resistance between the appropriate signal circuit terminal listed below and ground: Front vertical up switch terminal G Front vertical down switch terminal E Rear vertical up switch terminal H Rear vertical down switch terminal A Horizontal forward switch terminal F Horizontal rearward switch terminal C If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K40 Seat Memory Control Module. If Inactive
3. Install a 3 A fused jumper wire between the appropriate signal circuit terminal listed below and the ground circuit terminal D. Front vertical up switch terminal G Front vertical down switch terminal E Rear vertical up switch terminal H Rear vertical down switch terminal A Horizontal forward switch terminal F Horizontal rearward switch terminal C
4. Verify the scan tool seat switch parameter is Forward/Rearward or UP/Down. If not Forward/Rearward or UP/Down Ignition OFF, disconnect the harness connector at the K40 Seat Memory Control Module, 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. If less than 1 V Ignition OFF. Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K40 Seat Memory Control Module. If Forward/Rearward or UP/Down
5. Test or replace the S64D Seat Adjuster Switch - Driver.

Component Testing

Seat Adjuster Switch Test

1. Ignition OFF, disconnect the harness connector at the Seat Adjuster Switch - Driver.
2. Test for infinite resistance between the ground terminal D and each signal terminal with the switch in the open position. If less than infinite resistance Replace the Seat Adjuster Switch - Driver. If infinite resistance
3. Test for less than 2 ohms between the ground terminal D and each signal terminal with the appropriate switch in the closed position. If 2 ohms or greater Replace the Seat Adjuster Switch - Driver. If less than 2 ohms
4. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

1. «Driver or Passenger Seat Adjuster Switch Replacement»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
2. «Control Module References»(/buick/encore/i-2012-2016/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for K40 Seat Memory Control Module replacement, programming and setup

1. Perform the «Diagnostic System Check - Vehicle»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit Description

The seat memory control module monitors the position of the seat motors by using hall effect position sensors which are an internal part of each motor. The module supplies each sensor with a 12 V reference circuit and a low side signal circuit. During seat motor operation, the hall effect position sensor provides a determined number of pulse signals for every revolution of the motor shaft. The scan tool displays these pulse signals as counts that range from 0-65,535. The module counts the feedback pulses from each sensor to determine seat position and end of travel limits for each of the seat motors. High scan tool count values indicate forward or upward seat positions while low count values indicate rearward or downward seat positions.

1. DTC B1325 must not be present.
2. Module battery voltage must be between 9-16 V.

The seat memory control module does not detect position sensor movement or pulse signals while the adjuster motor is active. The following conditions will set this DTC

B2355 01, B2365 01, or B2375 01

The seat memory control module detects a voltage greater than 5 V on the sensor signal circuit.

B2355 06, B2365 06, or B2375 06

The seat memory control module detects a short to ground or an open on the sensor signal circuit.

1. With a short to ground or an open circuit, the seat memory control module disables the memory recall and easy exit/entry action commands of the motor monitored by the sensor. The motor will respond to manual position commands.
2. With a short to battery voltage, the seat memory control module disables the memory recall and easy exit/entry action commands for all four seat motors. The motors will respond to manual position commands.

1. The current DTC clears when the fault is no longer present and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Driver Seat Schematics (Encore) , Driver Seat Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition OFF, disconnect the harness connector at the appropriate driver seat motor listed below for which the DTC set: M50D Seat Front Vertical Motor - Driver M55D Seat Rear Vertical Motor - Driver M51D Seat Horizontal Motor - Driver
2. Ignition ON.
3. Test for greater than 10.8 V between the 12 V reference circuit terminal 2 and ground. If 10.8 V or less Ignition OFF, disconnect the X1 harness connector at the K40 Seat Memory Control Module. Test for infinite resistance between the 12 V reference circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the 12 V reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K40 Seat Memory Control Module. If greater than 10.8 V
4. Test for 0.2-2.0 V between the signal circuit terminal 4 and ground. If less than 0.2 V Ignition OFF, disconnect the X1 harness connector at the K40 Seat Memory Control Module. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K40 Seat Memory Control Module. If greater than 2.0 V Ignition OFF, disconnect the X1 harness connector at the K40 Seat Memory Control Module, ignition ON. Test for less than 1 V between the signal circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K40 Seat Memory Control Module. If between 0.2-2.0 V
5. Test or replace the seat motor.

Perform the Diagnostic Repair Verification after completing the repair.

1. «Front Seat Tilt Adjuster Actuator Replacement»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
2. «Driver or Passenger Seat Vertical Adjuster Actuator Replacement»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
3. «Front Seat Adjuster Actuator Replacement»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
4. «Control Module References»(/buick/encore/i-2012-2016/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for K40 Seat Memory Control Module replacement, programming and setup

1. Perform the «Diagnostic System Check - Vehicle»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The seat memory control module controls the seat motors via half bridges that are connected to power rails internal to the module. The seat memory control module connects all of the motor control circuits on each power rail to a common reference point whenever they are not in operation. This reference point is biased to approximately 2.5 V. The seat memory control module checks to see if this reference voltage is shorted to ground or battery before enabling any seat motor.

When a power seat switch is pressed or when a memory recall is requested, each seat motor receives battery voltage and ground from the seat memory control module via the motor control circuits. All motors are reversible, so the direction the motor rotates depends on which control circuit voltage is applied and which control circuit ground is applied. When the switch is operated in the opposite direction, the module reverses the polarity and applies voltage and ground to the opposite circuits to move the seat in the opposite direction.

1. DTC B1325 must not be present.
2. Module battery voltage must be between 9-16 V.

B3920 00

Current out of the module does not match the current returning to the module from 1.5-5 A.

B3920 01

The voltage on any power rail 1 motor control circuit exceeds 2.78 V for 100 ms.

B3920 02

The voltage on any power rail 1 motor control circuit is below 1.47 V for 100 ms.

B3920 42

This DTC will set if the module calibration is not programmed.

B3920 0B

The differential current measured through the high and low side of the power rail is within tolerance of each other, but the absolute current or an over-current has exceeded the maximum value.

The seat memory control module will not allow operation of any motor on the power rail for which the DTC was set.

1. The current DTC clears when the fault is no longer present and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Driver Seat Schematics (Encore) , Driver Seat Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

B3920 01 or B3920 02

1. Ignition OFF, disconnect the X4 and X5 harness connectors at the K40 Seat Memory Control Module.
2. Test for infinite resistance between the control circuit terminals listed below and ground: Front vertical motor up control terminal 7 X4 Front vertical motor down control terminal 8 X4 Rear vertical motor up control terminal 4 X5 Rear vertical motor down control terminal 3 X5 Horizontal motor forward control terminal 2 X5 Horizontal motor rearward control terminal 1 X5 If less than infinite resistance Repair the short to ground on the circuit. If infinite resistance
3. Ignition ON.
4. Test for less than 1 V between the control circuit terminals listed below and ground: Front vertical motor up control terminal 7 X4 Front vertical motor down control terminal 8 X4 Rear vertical motor up control terminal 4 X5 Rear vertical motor down control terminal 3 X5 Horizontal motor forward control terminal 2 X5 Horizontal motor rearward control terminal 1 X5 If 1 V or greater Repair the short to voltage on the circuit. If less than 1 V
5. Replace the K40 Seat Memory Control Module.

B3920 00 or B3920 0B

1. Ignition ON.
2. Clear the current and history DTC.
3. Determine which motor set this DTC by operating the driver seat motors listed below one at a time in both directions. Check for the DTC to set between each motor test. M50D Seat Front Vertical Motor - Driver M55D Seat Rear Vertical Motor - Driver M51D Seat Horizontal Motor - Driver
4. Ignition OFF, disconnect the harness connector at the seat motor for which the DTC set, ignition ON.
5. Clear the DTC.
6. Verify that DTC B3920 00 or B3920 0B does not set while operating the seat motor adjuster switch in both directions. If DTC B3920 00 or B3920 0B sets Test for infinite resistance between control circuit terminal 1 and control circuit terminal 5. If less than infinite resistance, repair the short between the circuits. If infinite resistance Test for less than 2 ohms between the control circuit terminals listed below end to end: Terminal 1 Terminal 5 If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the seat motor. If DTC B3920 00 or B3920 0B does not set
7. Replace the seat motor.

B3920 42

1. Ignition ON.
2. Verify the DTC is not set. If the DTC is set Replace the K40 Seat Memory Control Module. If the DTC is not set
3. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

1. «Front Seat Tilt Adjuster Actuator Replacement»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
2. «Driver or Passenger Seat Vertical Adjuster Actuator Replacement»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
3. «Front Seat Adjuster Actuator Replacement»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
4. «Control Module References»(/buick/encore/i-2012-2016/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for K40 Seat Memory Control Module replacement, programming and setup

Symptoms - Power Seats

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

1. Perform the «Diagnostic System Check - Vehicle»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) 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»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system) «Memory Seats Description and Operation»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system) «Power Seats System Description and Operation»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system__power-seats-system-description-and-operation)

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the system. Refer to «Checking Aftermarket Accessories»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__checking-aftermarket-accessories) .
2. 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

1. «Lumbar Support Malfunction»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
2. «Memory Seat Feature Malfunction»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
3. «Power Seat Malfunction (Without Memory A45)»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system) , «Power Seat Malfunction (With Memory A45)»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)

1. Perform the «Diagnostic System Check - Vehicle»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The seat lumbar support is controlled through the seat lumbar support switch. Battery voltage is supplied at all times to the lumbar switch through a 15 A fuse located in the rear body fuse block. When the lumbar switch is in an inactive state, the switch contacts are closed to the switch ground circuit.

The lumbar motor is reversible. For example, when the lumbar forward switch is pressed to move the lumbar support forward, battery voltage is applied through the switch contacts and the lumbar motor forward control circuit to the motor. The motor is grounded through the lumbar motor rearward switch contacts and the lumbar motor rearward control circuit to the motor. The motor runs in order to drive the lumbar support forward toward the occupants back until the switch is released. Moving the lumbar support rearward works similarly to moving the lumbar support forward, except that battery positive voltage and ground are applied on opposite circuits causing the motor to run in the opposite direction.

Schematic Reference

1. «Driver Seat Schematics (Encore)»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system) , «Driver Seat Schematics (Trax)»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
2. «Passenger Seat Schematics (Encore)»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Description and Operation

Lumbar Support Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate S65 Seat Lumbar Support Switch. It may take up to 2 min for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal H and ground. If 10 ohms or greater Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
3. Ignition ON.
4. Verify a test lamp illuminates between the B+ circuit terminal E and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF. Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF. Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for greater than 10 ohms between each control circuit listed below and ground: Lumbar forward control circuit terminal A Lumbar rearward control circuit terminal D If 10 ohms or less, disconnect the harness connector at the M53 Seat Lumbar Support Motor and retest to verify if the short is in the circuit or the component. If greater than 10 ohms, test or replace the S65 Seat Lumbar Support Switch. If the test lamp illuminates
5. Ignition OFF, connect the harness connector at the S65 Seat Lumbar Support Switch and disconnect the harness connector at the M53 Seat Lumbar Support Motor.
6. Connect a test lamp between control circuit terminal A and control circuit terminal B, ignition ON.
7. Verify the test lamp turns ON when commanding the lumbar support Forward and Rearward using the S65 Seat Lumbar Support Switch. If the test lamp remains OFF during either of the commands Ignition OFF, disconnect the harness connector at the S65 Seat Lumbar Support Switch. Test for infinite resistance between each control circuit and ground. If less than Infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in each control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the S65 Seat Lumbar Support Switch. If the test lamp remains ON during either of the commands Ignition OFF, disconnect the harness connector at the S65 Seat Lumbar Support Switch, ignition ON. Test for less than 1 V between the signal circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the S65 Seat Lumbar Support Switch. If the test lamp turns ON during each of the commands
8. Test or replace the M53 Seat Lumbar Support Motor.

Lumbar Support Switch

1. Ignition OFF, disconnect the harness connector at the appropriate S65 Seat Lumbar Support Switch.
2. Test for infinite resistance between the B+ terminal E and each control terminal with the switch in the open position. If less than infinite resistance Replace the S65 Seat Lumbar Support Switch. If infinite resistance
3. Test for less than 2 ohms between the B+ terminal E and each control terminal with the appropriate switch in the closed position. If 2 ohms or greater Replace the S65 Seat Lumbar Support Switch. If less than 2 ohms
4. Test for less than 2 ohms between the ground terminal H and each control terminal with the switch in the open position. If 2 ohms or greater Replace the S65 Seat Lumbar Support Switch. If less than 2 ohms
5. All OK.

Seat Lumbar Support Motor

1. Ignition OFF, disconnect the harness connector at the M53 Seat Lumbar Support Motor.
2. Install a 30 A fused jumper wire between control terminal A 12 V.
3. Momentarily install a jumper wire between control terminal B and ground. The M53 Seat Lumbar Support Motor should momentarily perform the lumbar FORWARD function. If the motor does not perform the lumbar FORWARD function Replace the M53 Seat Lumbar Support Motor. If the motor performs the lumbar FORWARD function
4. Reverse the polarity of jumper wires; the lumbar motor should perform REARWARD function. If the motor does not perform the lumbar REARWARD function Replace the M53 Seat Lumbar Support Motor. If the motor performs the lumbar REARWARD function
5. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

1. «Driver or Passenger Seat Lumbar Control Switch Replacement»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
2. «Driver or Passenger Seat Back Cushion Frame Replacement»(/buick/encore/i-2012-2016/remont/seats/#seat-hardware-seat-trim-and-upholstery)

1. Perform the «Diagnostic System Check - Vehicle»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Low reference is supplied to the driver 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 pre-recorded seat positions stored in memory.

The seat memory control module must be awake when measuring voltage from either one of the memory seat switch signal circuits. Voltage readings of 0.0 V or 5 V are possible if the module is not fully awake and result in misdiagnosing the circuit.

Schematic Reference

Driver Seat Schematics (Encore) , Driver Seat Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON.
2. Verify that all manual driver power seat functions operate when being controlled by the power seat adjuster switches. If any seat function does not operate Refer to «Power Seat Malfunction (Without Memory A45)»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system) , «Power Seat Malfunction (With Memory A45)»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system) . If all seat functions operate
3. Verify that the memory recall personalization option is ON. Refer to the owners manual. If the memory recall personalization option is not ON Turn ON the option, refer to the Owners Manual. If the memory recall personalization option is ON
4. Refer to Circuit/System Testing.

1. Ignition OFF, disconnect the harness connector at the S47D Seat Memory Switch - Driver.
2. Test for less than 20 ohms between the low reference circuit terminal 1 and ground. If 20 ohms or greater Ignition OFF, disconnect the X2 harness connector at the K40 Seat Memory Control Module. Test for less than 2 ohms in the low reference circuit end to end If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K40 Seat Memory Control Module. If less than 20 ohms
3. Ignition ON, press a power seat switch in order to wake up the K40 Seat Memory Control Module.
4. 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 Ignition OFF, disconnect the X2 harness connector at the K40 Seat Memory Control Module. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K40 Seat Memory Control Module. If 9 V or greater
5. Ignition OFF, disconnect the X2 harness connector at the K40 Seat Memory Control Module, ignition ON.
6. 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. If less than 1 V
7. Test or replace the S47D Seat Memory Switch - Driver.

Driver Seat Memory Switch

1. Ignition OFF, disconnect the harness connector at the S47D Seat Memory Switch - Driver.
2. Test for infinite resistance between each signal terminal listed below and the low reference terminal 5 with the switch in the open position. Terminal 1 Terminal 6 If less than infinite resistance Replace the S47D Seat Memory Switch - Driver. If infinite resistance
3. Test for less than 2 ohms between the signal terminal 1 and the low reference terminal 5 while pressing the memory MEM button. If 2 ohms or greater Replace the S47D Seat Memory Switch - Driver. If less than 2 ohms
4. Test for 570-698 ohms between the signal terminal 6 and the low reference terminal 5 while pressing the memory 1 button. If not between 570-698 ohms Replace the S47D Seat Memory Switch - Driver. If between 570-698 ohms
5. Test for 1800-2209 ohms between the signal terminal 6 and the low reference terminal 5 while pressing the memory 2 button. If not between 1800-2209 ohms Replace the S47D Seat Memory Switch - Driver. If between 1800-2209 ohms
6. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

1. «Driver Seat Adjuster Memory Switch Replacement (Encore)»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
2. «Control Module References»(/buick/encore/i-2012-2016/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for K40 Seat Memory Control Module replacement, programming and setup

1. Perform the «Diagnostic System Check - Vehicle»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Battery voltage is supplied at all times to the seat adjuster switch through a 30 A fuse located in the rear body fuse block. When the seat switch is in a inactive state, the switch contacts are closed to the switch ground circuit.

All seat motors are reversible. For example, when the seat horizontal forward switch is pressed to move the entire seat forward, B+ is applied through the switch contacts and the seat horizontal motor forward control circuit to the motor. With the horizontal motor rearward switch contacts closed to the switch ground circuit, the motor runs in order to drive the entire seat forward until the switch is released. Moving the entire seat rearward works similarly to moving the entire seat forward, except that battery voltage and ground are applied on opposite circuits causing the motor to run in the opposite direction. All seat motors are powered this way.

Schematic Reference

1. «Driver Seat Schematics (Encore)»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system) , «Driver Seat Schematics (Trax)»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
2. «Passenger Seat Schematics (Encore)»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Description and Operation

Power Seats System Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

1. Verify the driver or passenger power seat directional motors listed below operate when operating the seat switches in both directions. M50 Seat Front Vertical Motor M51 Seat Horizontal Motor M55 Seat Rear Vertical Motor If all seat motors do not operate Refer to Circuit/System Testing - Seat Adjuster Switch Circuit Test. If 1 or more seat motors operate Refer to Circuit/System Testing - Seat Motor Circuit Test.
2. All OK.

Seat Adjuster Switch Circuit Test

1. Ignition OFF, disconnect the harness connector at the appropriate S64 Seat Adjuster Switch.
2. Test for less than 10 ohms between the ground circuit terminal B and ground. If 10 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
3. Ignition ON.
4. Verify a test lamp illuminates between the B+ circuit terminal D and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the circuit breaker is not open and there is voltage at the circuit breaker. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF. Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for greater than 10 ohms between each signal circuit listed below and ground: Control circuit terminal E - M50 Seat Front Vertical Motor Control circuit terminal G - M50 Seat Front Vertical Motor Control circuit terminal A - M55 Seat Rear Vertical Motor Control circuit terminal H - M55 Seat Rear Vertical Motor Control circuit terminal F - M51 Seat Horizontal Motor Control circuit terminal C - M51 Seat Horizontal Motor If 10 ohms or less, disconnect the harness connector at the seat motor and retest to verify if the short is in the circuit or the component. If greater than 10 ohms, test or replace the S64 Seat Adjuster Switch. If the test lamp illuminates
5. Test or replace the S64 Seat Adjuster Switch.

Seat Motor Circuit Test

1. Ignition OFF, disconnect the harness connector at the appropriate seat motor listed below: M51 Seat Horizontal Motor M50 Seat Front Vertical Motor M55 Seat Rear Vertical Motor
2. Connect a test lamp between control circuit terminal 1 and control circuit terminal 3, ignition ON.
3. Verify the test lamp turns ON when commanding the seat motor Up and Down or Forward and Rearward using the seat adjuster switch. If the test lamp does not turn ON during either of the commands Ignition OFF, disconnect the harness connector at the S64 Seat Adjuster Switch. Test for less than 2 ohms in each control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, test or replace the S64 Seat Adjuster Switch If the test lamp turns ON during each of the commands
4. Test or replace the seat motor.

Seat Adjuster Switch

1. Ignition OFF, disconnect the harness connector at the S64 Seat Adjuster Switch.
2. Test for infinite resistance between the B+ terminal D and each control terminal with the switch in the open position. If less than infinite resistance Replace the S64 Seat Adjuster Switch.
3. Test for less than 2 ohms between the B+ terminal D and each control terminal with the appropriate switch in the closed position. If 2 ohms or greater Replace the S64 Seat Adjuster Switch. If less than 2 ohms
4. Test for less than 2 ohms between the ground terminal B and each control terminal listed below with the switch in the open position. If 2 ohms or greater Replace the S64 Seat Adjuster Switch. If less than 2 ohms
5. All OK.

Seat Motor

1. Ignition OFF, disconnect the harness connector at the appropriate seat motor listed below: M51 Seat Horizontal Motor M50 Seat Front Vertical Motor M55 Seat Rear Vertical Motor
2. Install a 30 A fused jumper wire between control terminal 1 and 12 V.
3. Momentarily install a jumper wire between control terminal 3 and ground. The seat motor should momentarily perform the appropriate FORWARD/ REARWARD/ UP/ DOWN function. If the motor does not perform the FORWARD/ REARWARD/ UP/ DOWN function Replace the motor. If the motor performs the FORWARD/ REARWARD/ UP/ DOWN function
4. Reverse the jumper wires; the motor should perform UP/ DOWN function. If the motor does not perform the FORWARD/ REARWARD/ UP/ DOWN function Replace the motor. If the motor performs the FORWARD/ REARWARD/ UP/ DOWN function
5. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

1. «Driver or Passenger Seat Adjuster Switch Replacement»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
2. «Front Seat Tilt Adjuster Actuator Replacement»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
3. «Driver or Passenger Seat Vertical Adjuster Actuator Replacement»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
4. «Front Seat Adjuster Actuator Replacement»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)

1. Perform the «Diagnostic System Check - Vehicle»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/buick/encore/i-2012-2016/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Battery voltage is supplied at all times to the seat memory control module through a 25 A fuse located in the underhood fuse block. This voltage is used by the module for logic power. Battery positive voltage is also supplied at all times to the seat memory control module through a 30 A fuse located in the rear body fuse block. This voltage is connected to a power rail internal to the seat memory control module and is used to drive the power seat motors and the seat heater elements on vehicles equipped with heated seats. Each seat motor is controlled by the seat memory control module through 2 motor control circuits. The seat memory control module connects all motor control circuits on the power rail to a common reference point whenever they are not in operation. This reference point is biased to approximately 2.5 V. The seat memory control module checks to see if the reference voltage is shorted to ground or battery before enabling any of the seat motors.

All motors are reversible. For example, when the seat switch is operated to move the entire seat forward, the switch signal circuit from the seat memory control module is pulled low indicating the entire seat forward command. In response to this signal, the seat memory control module applies battery voltage through the driver seat horizontal motor forward control circuit and ground through the driver seat horizontal motor rearward control circuit to the motor. The motor runs to drive the entire seat forward until the switch is released. Moving the entire seat rearward works similarly to moving the entire seat forward, except that battery positive voltage and ground are applied on the opposite circuits causing the motor to run in the opposite direction.

Schematic Reference

Driver Seat Schematics (Encore) , Driver Seat Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/buick/encore/i-2012-2016/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

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 switch. Driver Seat Horizontal Switch Driver Seat Cushion Front Vertical Switch Driver Seat Cushion Rear Vertical Switch If the parameter does not change Refer to Circuit/System Testing - Driver Seat Adjuster Switch Circuit Test. If the parameter changes
3. Verify the seat directional motors listed below operate while operating the appropriate driver seat switches in both directions. M50D Seat Front Vertical Motor - Driver M51D Seat Horizontal Motor - Driver M55D Seat Rear Vertical Motor - Driver If any seat motor does not operate Refer to Circuit/System Testing - Seat Motor Control Circuit Test. If all seat motors operate
4. All OK.

Driver Seat Adjuster Switch Circuit Test

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S64D Seat Adjuster Switch - Driver. It may take up to 2 min for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal D and ground. If 10 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
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 If not Inactive Ignition OFF, disconnect the harness connector at the K40 Seat Memory Control Module. Test for infinite resistance between the appropriate signal circuit terminal listed below and ground: Front vertical up switch terminal G Front vertical down switch terminal E Rear vertical up switch terminal H Rear vertical down switch terminal A Horizontal forward switch terminal F Horizontal rearward switch terminal C If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K40 Seat Memory Control Module. If Inactive
4. Install a 3 A fused jumper wire between the appropriate signal circuit terminal listed below and the ground circuit terminal D. Front vertical up switch terminal G Front vertical down switch terminal E Rear vertical up switch terminal H Rear vertical down switch terminal A Horizontal forward switch terminal F Horizontal rearward switch terminal C
5. Verify the scan tool seat switch parameter is Forward/Rearward or UP/Down. If not Forward/Rearward or UP/Down Ignition OFF, disconnect the harness connector at the K40 Seat Memory Control Module, 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. If less than 1 V Ignition OFF. Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K40 Seat Memory Control Module. If Forward/Rearward or UP/Down
6. Test or replace the S64D Driver Seat Adjuster Switch.

Seat Motor Control Circuit Test

1. Ignition OFF, disconnect the X4 harness connector at the K40 Seat Memory Control Module.
2. Test for less than 10 ohms between the ground circuit terminal 6 and ground. If 10 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
3. Ignition ON.
4. Verify that a test lamp illuminates between the B+ circuit terminal 5 and ground. If the test lamp does not illuminate Ignition OFF. Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp illuminates
5. Ignition OFF, connect the X4 harness connector at the K40 Seat Memory Control Module and disconnect the harness connector at the appropriate seat motor listed below: M50D Seat Front Vertical Motor - Driver M51D Seat Horizontal Motor - Driver M55D Seat Rear Vertical Motor - Driver
6. Connect a test lamp between control circuit terminal 1 and control circuit terminal 3, ignition ON.
7. Verify the test lamp illuminates when commanding the seat motor in the Up/Down or Forward/Rearward states with a scan tool. If the test lamp does not illuminate during either of the commands Ignition OFF, disconnect the X4 harness connector at the K40 Seat Memory Control Module. Test for infinite resistance between each control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in each control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K40 Seat Memory Control Module. If the test lamp illuminates during each of the commands
8. Test or replace the seat motor.

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 D and each signal terminal with the switch in the open position. If less than infinite resistance Replace the S64D Seat Adjuster Switch - Driver. If infinite resistance
3. Test for less than 2 ohms between the ground terminal D and each signal terminal with the appropriate switch in the closed position. If 2 ohms or greater Replace the S64D Seat Adjuster Switch - Driver. If less than 2 ohms
4. All OK.

Seat Motor

1. Ignition OFF, disconnect the harness connector at the appropriate seat motor listed below: M50D Seat Front Vertical Motor - Driver M51D Seat Horizontal Motor - Driver M55D Seat Rear Vertical Motor - Driver
2. Install a 30 A fused jumper wire between control terminal 1 and 12 V.
3. Momentarily install a jumper wire between control terminal 3 and ground. The seat motor should momentarily perform the appropriate FORWARD/ REARWARD/ UP/ DOWN function. If the motor does not perform the FORWARD/ REARWARD/ UP/ DOWN function Replace the motor. If the motor performs the FORWARD/ REARWARD/ UP/ DOWN function
4. Reverse the jumper wires; the motor should perform FORWARD/ REARWARD/ UP/ DOWN function. If the motor does not perform the FORWARD/ REARWARD/ UP/ DOWN function Replace the motor. If the motor performs the FORWARD/ REARWARD/ UP/ DOWN function
5. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

1. «Driver or Passenger Seat Adjuster Switch Replacement»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
2. «Front Seat Tilt Adjuster Actuator Replacement»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
3. «Driver or Passenger Seat Vertical Adjuster Actuator Replacement»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
4. «Front Seat Adjuster Actuator Replacement»(/buick/encore/i-2012-2016/remont/seats/#power-seat-system)
5. «Control Module References»(/buick/encore/i-2012-2016/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for K40 Seat Memory Control Module replacement, programming and setup

Scheme 49

Driver or Passenger Seat Adjuster Switch Replacement

Scheme 50

Driver Seat Adjuster Memory Switch Replacement (Encore)

Scheme 51

Driver or Passenger Seat Adjuster Memory Module Replacement (Encore)

Scheme 52

Front Seat Tilt Adjuster Actuator Replacement

Scheme 53

Driver or Passenger Seat Vertical Adjuster Actuator Replacement

Scheme 54

Front Seat Adjuster Actuator Replacement

Scheme 55

Driver or Passenger Seat Lumbar Control Switch Replacement

Lumbar Support Components

The power seat lumbar support systems each consist of the following components

1. Seat lumbar support switch
2. Lumbar support motor

The seat lumbar support switch provides both power and ground to the lumbar support motor. The motor contains an electronic circuit breaker (PTC) that will reset only after voltage has been removed from the motor. The motor moves the lumbar support forward and rearward.

When the lumbar switch is operated to move the lumbar support forward, battery positive voltage is applied through the lumbar forward switch contacts and the lumbar motor forward control circuit to the lumbar support motor. The motor is grounded through the lumbar rearward switch contacts and the lumbar motor rearward control circuit to the lumbar motor. The motor runs to drive the lumbar support forward toward the occupant's back until the switch is released. Moving the lumbar support rearward works similarly to moving the lumbar support forward, except that battery voltage and ground are applied on opposite circuits causing the motor to run in the opposite direction.

Memory Seat System Components

The memory seat system consists of the following components

1. Driver seat adjuster switch
2. Driver seat memory switch
3. Seat memory control module
4. Seat horizontal motor/sensor
5. Seat front vertical motor/sensor
6. Seat rear vertical motor/sensor

Scheme 56

Driver Seat Personalization Option

The seat memory control module will not perform remote memory recall and driver seat easy exit functions unless these personalization options are activated in the audio system, refer to Vehicle Personalization in the Owner's Manual. The audio system reports the vehicle personalization option settings to the seat memory control module as well as other receiving modules via GMLAN message each time the ignition switch is cycled to the ON position. The seat memory control module will then store the seat personalization option settings and examine them before making a memory seat adjustment. The seat personalization option settings stored within the seat memory control module will not change until the memory recall option setting in the audio system is changed and the ignition switch is cycled to the ON position.

Driver Seat Adjuster Switch

Ground is supplied at all times to the driver seat adjuster switch through the switch ground circuit and ground connection. The seat memory control module supplies a low current voltage to each signal circuit of the seat adjuster switch. When the 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.

Seat Memory Switch

Memory recalls via the memory switch require the driver to press and hold the memory button until the seat reaches it's memory position.

Ground from the seat memory control module is supplied at all times through the low reference circuit to the driver seat memory switch. The module also supplies memory set and memory recall signal circuits to the seat memory switch. When a memory recall switch is pressed, the signal circuit from the seat memory control module is pulled low through the switch contacts and a 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 pre-recorded seat positions stored in memory.

Refer to the Owner's Manual for Storing Memory Positions, Recalling Memory Positions, Recalling RKE Memory Positions, and for the Easy Exit Driver Seat function.

Seat Motors

There are 3 motors that move the position of the seat. These are the seat horizontal motor, front vertical motor, and the rear vertical motor. The horizontal motor moves the entire seat forward and rearward. Both vertical motors run simultaneously when the seat switch is operated in order to move the entire seat up and down. Or they can be selected independently to vertically tilt the front or rear of the seat up and down.

The seat memory control module controls all seat motors via half bridges that are connected to a single power rail internal to the module. The module connects all motor outputs on the power rail to a common reference point whenever they are not in operation. This reference point is biased to approximately 2.5 V. The seat memory control module checks to see if this reference voltage is shorted to ground or battery before enabling any seat motor. All seat motors operate independently of each other. Each motor contains a electronic circuit breaker (PTC), which will reset only after voltage has been removed from the motor.

All seat motors are reversible. For example, when the seat switch is pressed to move the entire seat forward, ground is applied through the switch contacts and seat horizontal forward switch signal circuit to the seat memory control module. In response to this signal, the seat memory control module applies battery voltage through the driver seat horizontal motor forward control circuit and ground through the driver seat horizontal motor rearward control circuit to the motor. The motor runs in order to drive the entire seat forward. Moving the entire seat rearward works similarly to moving the entire seat forward, except that battery voltage and ground are applied on the opposite circuits causing the motor to run in the opposite direction. All of the seat motors are powered this way.

Seat Position Sensors

The seat motors are equipped with 2 wire hall effect type position sensors internal to the motor. The sensors are monitored by the seat memory control module and are used to determine seat positions when storing or recalling memory settings. The seat memory control module supplies the sensors with a common 12 V reference circuit and separate signal circuits. During seat motor operation, the hall effect position sensor provides a determined number of pulse signals for every revolution of the motor shaft. These pulse signals (Counts) range from 0 - 65,535. High scan tool count values indicate forward or upward seat positions while low count values indicate rearward or downward seat positions.

Power Seats System Description and Operation

The power seat system consists of the following components

1. Seat adjuster switch
2. Seat horizontal motor
3. Seat front vertical motor
4. Seat rear vertical motor

Note. If equipped, the passenger seat block diagram is identical to the driver seat.

Scheme 57

Motors

All of the seat motors operate independently of each other. Each motor contains an electronic circuit breaker (PTC) that opens in the event of a circuit overload and will reset only after voltage has been removed from the circuit. There are three seat position motors. These are the horizontal motor, front vertical motor, and the rear vertical motor. The horizontal motor moves the entire seat forward and rearward. The seat vertical motors may operate independently to tilt the front or rear of the seat cushion up or down. Both motors can also run simultaneously to move the entire seat up or down.

Seat Operation

The seat switches provide both power and ground to the selected seat motors. All seat motors are reversible. For example, when the seat horizontal forward switch is pressed to move the entire seat forward, ground is applied through the switch contacts and the seat horizontal motor forward control circuit to the motor. With the horizontal motor rearward switch contacts closed to the switch B+ circuit, the motor runs in order to drive the entire seat forward until the switch is released. Moving the entire seat rearward works similarly to moving the entire seat forward, except that battery voltage and ground are applied on opposite circuits causing the motor to run in the opposite direction. All seat motors are powered this way.

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Control Module References
• Diagnostic Repair Verification
• Checking Aftermarket Accessories
• Driver or Passenger Seat Back Cushion Frame Replacement
• Fastener Caution
• DTC B1735, B1740, B1745, B1750, B1755, B1760, B1815, or B1820
• Power Seats System Description and Operation