Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | 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 | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Seat Adjuster Switch B+ | 1 | 1 | -- | -- |
Front Vertical Motor Down Control | 1 | 1 | -- | -- |
Front Vertical Motor Up Control | 1 | 1 | -- | -- |
Horizontal Motor Forward Control | 1 | 1 | -- | -- |
Horizontal Motor Rearward Control | 1 | 1 | -- | -- |
Rear Vertical Motor Down Control | 1 | 1 | -- | -- |
Rear Vertical Motor Up Control | 1 | 1 | -- | -- |
Seat Adjuster Switch Ground | -- | 1 | -- | -- |
1. Power seat inoperative | ||||
Circuit/System Description
The power seats are controlled through the seat adjuster switch. Battery voltage is supplied at all times to the driver and passenger seat adjuster switches through the SEAT 20A circuit breaker located in the I/P fuse block. When the seat 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
Connector End View Reference
Description and Operation
Power Seats System Description and Operation
Electrical Information Reference
Circuit/System Verification
Operate the appropriate power seat switches for the seat directional motors listed below in both directions. The seat should move in the commanded directions.
| • | Seat Horizontal Motor |
| • | Seat Front Vertical Motor |
| • | Seat Rear Vertical Motor |
| ⇒ | If all power seat functions are inoperative, refer to the Seat Adjuster Switch Circuit Test. |
| ⇒ | If 1 or more of the seat adjuster motors operate, refer to the Seat Adjuster Motor Circuit Test. |
Circuit/System Testing
Seat Adjuster Switch Circuit Test.
- Ignition OFF, disconnect the X1 harness connector at the appropriate seat adjuster switch.
- Test for less than 5 Ω between the ground circuit terminal 2 and ground.
- Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 1 and ground.
- If all circuits test normal, test or replace the seat adjuster switch.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. |
Seat Adjuster Motor Circuit Test
- Ignition OFF, disconnect the harness connector at the appropriate seat motor.
- Connect a test lamp between control circuit terminal 1 and control circuit terminal 2.
- Ignition ON, command the appropriate seat motor Up and Down or Forward and Rearward using the seat adjuster switch. The test lamp should turn ON when commanding the up and down or forward and rearward states.
- If all circuits test normal, test or replace the seat motor.
| ⇒ | If the test lamp remains OFF for either of the commands, test the control circuits for a short to ground or an open/high resistance. If the circuits test normal, test or replace the seat adjuster switch. |
Component Testing
Seat Adjuster Switch
- Ignition OFF, disconnect the harness connector at the appropriate seat adjuster switch.
- Test for infinite resistance between the B+ terminal 1 and each control terminal listed below with the switch in the open position:
- Test for less than 1 Ω between the B+ terminal 1 and each control terminal listed below with the switch in the closed position.
- Test for less than 1 Ω between the ground terminal 2 and each control terminal listed below with the switch in the open position.
| • | Seat front vertical up control terminal 3 |
| • | Seat front vertical down control terminal 4 |
| • | Seat horizontal forward control terminal 7 |
| • | Seat horizontal rearward control terminal 8 |
| • | Seat rear vertical up control terminal 5 |
| • | Seat rear vertical down control terminal 6 |
| ⇒ | If not the specified value, replace the seat adjuster switch. |
| • | Seat front vertical up control terminal 3 |
| • | Seat front vertical down control terminal 4 |
| • | Seat horizontal forward control terminal 7 |
| • | Seat horizontal rearward control terminal 8 |
| • | Seat rear vertical up control terminal 5 |
| • | Seat rear vertical down control terminal 6 |
| ⇒ | If greater than the specified range, replace the seat adjuster switch. |
| • | Seat front vertical up control terminal 3 |
| • | Seat front vertical down control terminal 4 |
| • | Seat horizontal forward control terminal 7 |
| • | Seat horizontal rearward control terminal 8 |
| • | Seat rear vertical up control terminal 5 |
| • | Seat rear vertical down control terminal 6 |
| ⇒ | If greater than the specified range, replace the seat adjuster switch. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
