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

Power seats without memory are completely controlled through the power seat switch. Battery voltage is supplied to the power seat switch through the LT/PWR/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 Testing

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

^ If not the specified value, 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. Disconnect the harness connector at the inoperative seat motor.
6. Connect a test lamp between the motor control circuits terminal 1 and terminal 2.
7. Activate the appropriate seat switch to the FORWARD/UP and REARWARD/DOWN directions. The test lamp should turn ON while activating the switch in the both directions.

^ If the test lamp remains OFF for either direction, test the motor control circuits for a short to ground or an open/high resistance. If the circuits test normal, test or replace the seat adjuster switch.

8. If all circuits test normal, replace the inoperative seat motor.

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 Lumbar Control Switch Replacement
* Front Seat Lumbar Support Replacement
* Front Seat Recliner Actuator Motor Replacement