Power Seat Inoperative (w/o A45)
Power Seat Inoperative (w/o A45)
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
Battery voltage is supplied at all times to the driver and passenger seat adjuster switches from the PWR SEATS MSM 30 amp circuit breaker that is located in the I/P fuse block. When a seat adjuster switch is in an inactive state, the switch contacts are closed to the switch ground circuit.
The power seat adjuster 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 operate this way.
Reference Information
Schematic Reference
* Driver Seat Schematics (Driver Seat Schematics)
* Passenger Seat Schematics (Passenger Seat Schematics)
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)
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the inoperative seat adjuster switch.
2. Ignition OFF, test for less than 1 ohm between the ground circuit terminal H and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Verify that a test lamp illuminates between the B+ circuit terminal E and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
4. Connect the harness connector at the inoperative seat adjuster switch.
5. Disconnect the harness connector at the inoperative seat adjuster motor assembly.
6. Connect a test lamp between the appropriate motor control circuit terminals for the inoperative adjuster motor.
7. Verify the test lamp illuminates while pressing the appropriate seat switch in both directions.
• If the test lamp does not illuminate for both switch directions, test the motor control circuits for a short to ground or an open/high resistance. If the circuits test normal, replace the inoperative seat adjuster switch.
8. If all circuits test normal, replace the inoperative seat adjuster motor assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Front Seat Adjuster Motor Replacement (Front Seat Adjuster Motor Replacement)
* Power Seat Switch Replacement (Power Seat Switch Replacement)