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, 2 | 1, 2 | 1, 2 | -- |
Horizontal Motor Forward Control | 1 | 1 | 1 | -- |
Horizontal Motor Rearward Control | 1 | 1 | 1 | -- |
Front Vertical Motor Front Up Control | 1 | 1 | 1 | -- |
Front Vertical Motor Front Down Control | 1 | 1 | 1 | -- |
Rear Vertical Motor Rear Up Control | 1 | 1 | 1 | -- |
Rear Vertical Motor Rear Down Control | 1 | 1 | 1 | -- |
Lumbar Motor Forward Control | 2 | 2 | 2 | -- |
Lumbar Motor Rearward Control | 2 | 2 | 2 | -- |
Seat Adjuster Switch Ground | -- | 1 | -- | -- |
Seat Lumbar Switch Ground | -- | 2 | -- | -- |
| ||||
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
Connector End View Reference
Description and Operation
Power Seats System Description and Operation
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the seat adjuster switch.
- Ignition OFF, verify that a test lamp illuminates between B+ and the ground circuit terminal E.
- Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal H and ground.
- Connect the harness connector at the seat adjuster switch.
- Ignition OFF, disconnect the harness connector at the seat adjuster motor assembly.
- Ignition OFF, test for less than 5.0 ohms of resistance between the appropriate motor control circuit terminal and ground.
- Connect a test lamp between the motor control circuit terminals for the inoperative motor.
- 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 all circuits test normal, test or replace the seat adjuster motor assembly.
| ⇒ | If the test lamp does not illuminate, 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. |
| ⇒ | 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. |
| ⇒ | 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
