Power Seat Inoperative w/o A45
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 completely controlled through the seat adjuster switch. Battery voltage is supplied at all times to the seat adjuster switch through the PWR SEATS 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 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
Ignition ON, operate the seat switches for the seat directional motors listed below in both directions. The seat should move in the commanded directions.
| • | Horizontal Motor |
| • | Front Vertical Motor |
| • | Rear Vertical Motor |
| ⇒ | If the power seat is inoperative in all directions, refer to the Seat Adjuster Switch Circuit Test. |
| ⇒ | If one or more of the seat adjuster motors operate, refer to the Seat Adjuster Motor Circuit Test. |
Circuit/System Testing
Seat Adjuster Switch Circuit Test
- Disconnect the harness connector at the appropriate seat adjuster switch.
- Test for less than 5 Ω between the ground circuit terminal H and ground.
- Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal A 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 adjuster motor assembly.
- Connect a test lamp between the appropriate control circuit terminals listed below:
- Ignition ON, command the 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 replace the seat adjuster motor assembly.
| • | Horizontal motor terminal A and terminal B |
| • | Front vertical motor terminal C and terminal D |
| • | Rear vertical motor terminal E and terminal F |
| ⇒ | If the test lamp remains OFF during either of the commands, test both 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 A and the control terminals listed below with the switch in the open position.
- Test for less than 1 Ω between the B+ terminal A and the control terminals listed below with the switch in the closed position.
- Test for less than 1 Ω between the ground terminal H and the control terminals listed below with the switch in the open position.
| • | Horizontal motor forward control terminal E |
| • | Horizontal motor rearward control terminal D |
| • | Front vertical motor upward control terminal F |
| • | Front vertical motor downward control terminal G |
| • | Rear vertical motor upward control terminal B |
| • | Rear vertical motor downward control terminal C |
| ⇒ | If not the specified value, replace the seat adjuster switch. |
| • | Horizontal motor forward control terminal E |
| • | Horizontal motor rearward control terminal D |
| • | Front vertical motor upward control terminal F |
| • | Front vertical motor downward control terminal G |
| • | Rear vertical motor upward control terminal B |
| • | Rear vertical motor downward control terminal C |
| ⇒ | If greater than the specified range, replace the seat adjuster switch. |
| • | Horizontal motor forward control terminal E |
| • | Horizontal motor rearward control terminal D |
| • | Front vertical motor upward control terminal F |
| • | Front vertical motor downward control terminal G |
| • | Rear vertical motor upward control terminal B |
| • | Rear vertical motor downward control terminal C |
| ⇒ | If greater than the specified range, replace the seat adjuster switch. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
