Diesel Data: Automotive Repair

Power Seat Inoperative (Without Memory)



POWER SEAT INOPERATIVE (W/O MEMORY)

DIAGNOSTIC FAULT INFORMATION
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview

CIRCUIT/SYSTEM DESCRIPTION
Power seats without memory are completely controlled through the power seat switch. Battery voltage is supplied to the power seat switch through the power seat circuit breaker. While the seat adjuster switches are in an inactive state the switch contacts are closed to the power seat switch ground circuit. When a power seat switch is pressed to an active state the switch contact is closed to the battery voltage supply circuit. Each seat adjuster motor is controlled by the power seat switch through 2 motor control circuits. The seat adjuster motors are bidirectional and the direction of adjuster motor rotation is determined by which of the adjuster motor control circuits is switched to battery voltage while the other remains grounded.

CIRCUIT/SYSTEM TESTING
1. Disconnect the seat adjuster or power lumbar switch connector.
2. Verify that a test lamp illuminates when connected from battery voltage to the ground circuit terminal.
- If the test lamp does not illuminate, repair the ground circuit for an open/high resistance.
3. Verify that a test lamp illuminates when connected from the battery supply circuit terminal to ground.
- If the test lamp does not illuminate, repair the battery supply circuit for an open/high resistance or short to ground.
4. Connect the seat adjuster or power lumbar switch connector and disconnect the inoperative motor assembly connector.
5. Connect a test lamp across the inoperative motor control circuit terminals.
6. Verify that the test lamp illuminates when the appropriate switch is pressed.
- If the test lamp does not illuminate, repair the motor circuits for an open/high resistance or short to ground. If the circuits test normal replace the seat adjuster or power lumbar switch.
7. If the circuits test normal, replace the inoperative motor assembly.

REPAIR INSTRUCTIONS
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- Power Seat Switch Replacement
- Front Seat Adjuster Replacement (Power)
- Lumbar Switch Replacement
- Front Seat Lumbar Support Replacement (Power)
- Front Seat Recliner Actuator Motor Replacement Verification Tests