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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.



Circuit/System Description

The power seat is controlled through the seat adjuster switch. Battery voltage is supplied at all times to the seat adjuster switch from the PWR/SEAT 30A circuit breaker that is located in the underhood fuse block. When the seat adjuster switches are in an 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, 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 ([1][2]Electrical 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)for Scan Tool Information


Circuit/System Verification

Ignition ON, command the driver seat FORWARD and REARWARD, FRONT DOWN and FRONT UP, REAR DOWN and REAR UP using the driver seat adjuster switch. The driver seat should perform the FORWARD, REARWARD, FRONT DOWN, FRONT UP, REAR DOWN and REAR UP functions.


Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the driver seat adjuster switch.
2. Ignition OFF, test for less than 1 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. 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. Ignition OFF, connect the harness connector at the driver seat adjuster switch and disconnect the harness connector at the appropriate seat motor.
5. Ignition OFF, test for less than 1 ohm of resistance between the control circuit terminal 1 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, test or replace the driver seat adjuster switch.

6. Ignition OFF, test for less than 1 ohm of resistance between the control circuit terminal 2 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, test or replace the driver seat adjuster switch.

7. Connect a test lamp between control circuit terminal 1 and control circuit terminal 2.
8. Ignition ON, command the appropriate seat motor in both directions using the driver seat adjuster switch. The test lamp should illuminate when commanding the each direction.

• If the test lamp does not illuminate during either of the commands, test both control circuits for a short to ground. If the circuits test normal, test or replace the driver seat adjuster switch.

9. If all circuits tests normal, test or replace the appropriate seat motor.



Component Testing


Driver Seat Adjuster Switch
1. Ignition OFF, disconnect the harness connector at the driver seat adjuster switch.
2. Test for infinite resistance between the control terminals F and C and the B+ terminal D with the switch in the INACTIVE position.

• If less than the specified value, replace the driver seat adjuster switch.

3. Test for less than 2 ohms of resistance between the control terminal F and the B+ terminal D with the switch in the REARWARD position.

• If greater than the specified range, replace the driver seat adjuster switch.

4. Test for less than 2 ohms of resistance between the control terminal C and the B+ terminal D with the switch in the FORWARD position.

• If greater than the specified range, replace the driver seat adjuster switch.

5. Test for infinite resistance between the control terminals A and H and the B+ terminal D with the switch in the INACTIVE position.

• If less than the specified value, replace the driver seat adjuster switch.

6. Test for less than 2 ohms of resistance between the control terminal A and the B+ terminal D with the switch in the FRONT DOWN position.

• If less than the specified value, replace the driver seat adjuster switch.

7. Test for less than 2 ohms of resistance between the control terminal H and the B+ terminal D with the switch in the FRONT UP position.

• If greater than the specified range, replace the driver seat adjuster switch.

8. Test for infinite resistance between the control terminals G and E and the B+ terminal D with the switch in the INACTIVE position.

• If less than the specified value, replace the driver seat adjuster switch.

9. Test for less than 2 ohms of resistance between the control terminal G and the B+ terminal D with the switch in the REAR DOWN position.

• If less than the specified value, replace the driver seat adjuster switch.

10. Test for less than 2 ohms of resistance between the control terminal E and the B+ terminal D with the switch in the REAR UP position.

• If less than the specified value, replace the driver seat adjuster switch.




Seat Motor
1. Install a 30-amp fused jumper wire between the control terminal 1 and 12 volts. Momentarily install a jumper wire between the control terminal 2 and ground. The appropriate seat motor should perform the UP/DOWN/FORWARD/REARWARD function.

• If the function does not perform as specified, replace the appropriate seat motor.

2. Reverse the jumper wires; the appropriate seat motor should perform the UP/DOWN/FORWARD/REARWARD function.

• If the function does not perform as specified, replace the appropriate seat motor.




Repair Instructions

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


Power Seat Switch Replacement (Power Seat Switch Replacement)

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