Power Seat Inoperative (w/o Memory)
Power Seat Inoperative (w/o Memory)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach
* Diagnostic Procedure Instructions provides an overview of each diagnostic category
Diagnostic Fault Information
Circuit/System Description
Power seats without memory are completely controlled through the power seat switch. Battery voltage is supplied to the power seat switch through the power seat circuit breaker. While the seat adjuster switches are in an inactive state the switch contacts are closed to the power seat switch ground circuit. When a power seat switch is pressed to an active state the switch contact is closed to the battery voltage supply circuit. Each seat adjuster motor is controlled by the power seat switch through 2 motor control circuits. The seat adjuster motors are bidirectional and the direction of adjuster motor rotation is determined by which of the adjuster motor control circuits is switched to battery voltage while the other remains grounded.
Circuit/System Verification
1. Operate the horizontal, front vertical, and rear vertical switches in both directions.
^ If the power seat is inoperative in all directions, refer to Power Seat Switch Circuit Test.
^ If 1 or 2 of the seat adjuster motors operate, refer to Seat Adjuster Circuit Test.
2. Operate the recline in both directions.
^ If the recline function is inoperative, refer to Recliner Actuator Circuit Test.
3. Operate the horizontal and vertical lumbar switches in both directions.
^ If both lumbar functions are inoperative, refer to Lumbar Switch Circuit Test.
^ If 1 lumbar function is inoperative, refer to Lumbar Support Circuit Test.
Circuit/System Testing
Power Seat Switch Circuit Test
1. Disconnect the harness connector at the power seat switch.
2. Verify that a test lamp illuminates between the ground circuit terminal B and B+.
^ If the test lamp does not illuminate, repair the ground circuit for an open/high resistance.
3. Verify that a test lamp illuminates between the listed B+ circuit terminal and ground.
* With AN3 terminal E
* Without AN3 terminal D
^ If the test lamp does not illuminate, repair the B+ circuit for an open/high resistance or short to ground.
4. If all circuits test normal, test or replace the power seat switch.
Lumbar Switch Circuit Test
1. Disconnect the harness connector at the lumbar switch.
2. Verify that a test lamp illuminates between the ground circuit terminal E and B+.
^ If the test lamp does not illuminate, repair the ground circuit for an open/high resistance.
3. Verify that a test lamp illuminates between the B+ circuit terminal G and ground.
^ If the test lamp does not illuminate, repair the B+ circuit for an open/high resistance or short to ground.
4. If all circuits test normal, test or replace the lumbar switch.
Seat Adjuster Circuit Test
1. Ignition OFF, disconnect the harness connector at the seat adjuster assembly.
2. Ignition OFF, test for less than 1.0 ohm between the affected control circuit terminal listed and ground.
* Rear vertical terminal 1
* Front vertical terminal 2
* Horizontal terminal 3
^ If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the power seat switch.
3. Ignition OFF, test for less than 1.0 ohm between the affected control circuit terminal listed and ground.
* Rear vertical terminal 4
* Front vertical terminal 5
* Horizontal terminal 6
^ If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the power seat switch.
4. Connect a test lamp between the affected control circuit terminals listed.
* Rear vertical terminal 1 to terminal 4
* Front vertical terminal 2 to terminal 5
* Horizontal terminal 3 to terminal 6
5. Operate the affected switch in both directions. The test lamp should turn ON when the switch is pressed in both directions.
^ If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, replace the power seat switch.
6. If all circuits test normal, test or replace the seat adjuster.
Recliner Actuator Circuit Test
1. Ignition OFF, disconnect the harness connector at the redline motor.
2. Ignition OFF, test for less than 1.0 ohm between the control circuit terminal A and ground.
^ If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the power seat switch.
3. Ignition OFF, test for less than 1.0 ohm between the control circuit terminal B and ground.
^ If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the power seat switch.
4. Connect a test lamp between control circuit terminal A and control circuit terminal B.
5. Operate the recline switch in both directions. The test lamp should turn ON when the switch is pressed in both directions.
^ If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, replace the power seat switch.
6. If all circuits test normal, test or replace the recliner motor.
Lumbar Support Circuit Test
1. Ignition OFF, disconnect the harness connector at the lumbar adjuster assembly.
2. Ignition OFF, test for less than 1.0 ohm between the affected control circuit terminal listed and ground.
* Vertical lumbar terminal A
* Horizontal lumbar terminal C
^ If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace the lumbar switch.
3. Ignition OFF, test for less than 1.0 ohm between the affected control circuit terminal listed and ground.
* Vertical lumbar terminal B
* Horizontal lumbar terminal D
^ If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace the lumbar switch.
4. Connect a test lamp between affected control circuit terminals listed.
* Vertical lumbar terminal A to terminal B
* Horizontal lumbar terminal C to terminal D
5. Operate the affected switch in both directions. The test lamp should turn ON when the switch is pressed in both directions.
^ If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, replace the lumbar switch.
6. If all circuits test normal, test or replace the lumbar support.
Component Testing
Seat Adjuster Switch Test
1. Ignition OFF, disconnect the harness connector at the seat adjuster switch.
2. Test for infinite resistance between each control terminal and the B+ terminal with the switch in the open position.
^ If less than the specified value, replace the seat adjuster switch.
3. Test for less than 1 ohm between each control terminal and the B+ terminal with the switch in the closed position.
^ If greater than the specified range, replace the seat adjuster switch.
4. Test for less than 1 ohm between each control terminal and the ground terminal with the switch in the open position.
^ If greater than the specified range, replace the seat adjuster switch.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests
* Power Seat Switch Replacement
* Front Seat Adjuster Replacement (Power)
* Lumbar Switch Replacement
* Front Seat Lumbar Support Replacement
* Front Seat Recliner Actuator Motor Replacement