Power Seat Inoperative

Power Seat Inoperative

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

Diagnostic Fault Information





Circuit/System Description

Battery voltage is supplied at all times to the seat adjuster switch from the PWR SEAT 25 A circuit breaker located in the I/P fuse block. When the seat adjuster switches are in an inactive state, the switch contacts are closed to the switch ground circuit.

All power seat motors are reversible. For example, when the seat horizontal forward switch is pressed to move the entire seat forward, battery voltage is applied through the switch contacts and the seat horizontal motor forward control circuit to the motor. The motor is grounded through the horizontal motor rearward switch contacts and the horizontal motor rearward control circuit to the motor. 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 positive voltage and ground are applied on opposite circuits causing the motor to run in the opposite direction. All seat motors are powered this way.

Reference Information
Schematic Reference

Driver Seat Schematics (Driver Seat Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Power Seats System Description and Operation (Power Seats System Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning)

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the inoperative seat adjuster switch.
2. Ignition OFF, verify that a test lamp illuminates between B+ and the ground circuit terminal B.

• If the test lamp does not illuminate, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal D 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 inoperative seat adjuster motor assembly.
6. Ignition OFF, test for less than 5.0 ohms of resistance between the appropriate motor control circuit terminal and ground.

• If greater than the specified range, test the motor control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the seat adjuster switch.

7. Connect a test lamp between the motor control circuit terminals for the inoperative motor.
8. Ignition ON, operate the appropriate seat adjuster switch in both directions. The test lamp should turn ON and OFF as the seat adjuster switch is operated.

• If the test lamp does not illuminate for both directions, test the motor control circuits for a short to ground or an open/high resistance. If the circuits test normal replace the seat adjuster switch.

9. If all circuits test normal, test or replace the inoperative seat adjuster motor assembly.

Repair Instructions

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

* Power Seat Switch Replacement (Power Seat Switch Replacement)
* Power Seat Adjuster Mechanism Replacement (Power Seat Adjuster Mechanism Replacement)