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.

Circuit/System Description

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. Verify operation of all power seat functions from the seat adjuster switch.

^ If any of the seat adjuster switch functions are inoperative, refer to Adjuster Motor Control Circuit Test.

2. Verify operation of the horizontal lumbar function.

^ If the horizontal lumbar function is inoperative, refer to Lumbar Motor Control Circuit Test.

Circuit/System Testing

Adjuster Motor Control Circuit Test

1. Ignition OFF, disconnect the harness connector at the seat adjuster switch.
2. Test for less than 1.0 ohm of resistance between the ground circuit terminal B and ground.

^ If greater than the specified range, test the ground circuit for an open/high resistance.

3. Verify that a test lamp illuminates between the B+ circuit terminal E and ground.

^ If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

4. Connect the harness connector at the seat adjuster switch.
5. Ignition OFF, disconnect the harness connector at the affected seat motor.
6. Ignition OFF, test for less than 1.0 ohm of resistance between the control circuit terminal A and ground.

^ If greater than the specified range, test the control circuit for an open/high resistance. If circuits test normal, replace the seat adjuster switch.

7. Ignition OFF, test for less than 1.0 ohm of resistance between the control circuit terminal B and ground.

^ If greater than the specified range, test the control circuit for an open/high resistance. If circuits test normal, replace the seat adjuster switch.

8. Connect a test lamp between control circuit terminal A and control circuit terminal B.
9. Operate the affected seat switch in both directions. The test lamp should turn ON when commanding the motor 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 seat adjuster switch.

10. If all circuits test normal, test or replace the affected motor assembly.

Lumbar Motor Control Circuit Test

1. Ignition OFF, disconnect the harness connector at the lumbar switch.
2. Test for less than 1.0 ohm of resistance between the ground circuit terminal H and ground.

^ If greater than the specified range, test the ground circuit for an open/high resistance.

3. Verify that a test lamp illuminates between the B+ circuit terminal E and ground.

^ If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

4. Connect the harness connector at the lumbar switch.
5. Ignition OFF, disconnect the harness connector at the lumbar motor.
6. Ignition OFF, test for less than 1.0 ohm of resistance between the control circuit terminal A and ground.

^ If greater than the specified range, test the control circuit for an open/high resistance. If circuits test normal, replace the lumbar switch.

7. Ignition OFF, test for less than 1.0 ohm of resistance between the control circuit terminal B and ground.

^ If greater than the specified range, test the control circuit for an open/high resistance. If circuits test normal, replace the lumbar switch.

8. Connect a test lamp between control circuit terminal A and control circuit terminal B.
9. Operate the lumbar switch in both directions. The test lamp should turn ON when commanding the motor 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.

10. If all circuits test normal, test or replace the lumbar motor assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Power Seat Switch Replacement
* Front Seat Lumbar Control Switch Replacement
* Power Seat Adjuster Mechanism Replacement
* Front Seat Lumbar Support Replacement