Front Seat Cushion Side Bolster Malfunction
Front Seat Cushion Side Bolster Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
Battery voltage is supplied at all times to the driver and passenger seat bolster adjuster switches through 15 A fuses located in the rear fuse block. When either bolster switch is pressed to inflate the seat cushion or seat back bolsters, battery voltage is applied through the switch contacts and the inflate signal circuit to the bolster adjuster valve. In response to this signal, the bolster adjuster valve energizes its internal inflate solenoid and applies battery voltage through the seat lumbar/bolster pump control circuit to the pump. The pump runs to inflate the appropriate support bladder until the switch is released. When the switch is pressed to deflate the bolster, battery voltage is applied through the switch contacts and the deflate signal circuit to the bolster adjuster valve. The bolster adjuster valve energizes its internal deflate solenoid and air is released from the bladder until the switch is released. Ground for the seat bolster adjuster valve and the seat lumbar/bolster pump is supplied at G200 for the driver seat and G201 for the passenger seat.
Reference Information
Schematic Reference
* Driver Seat Schematics Driver Seat Schematics
* Passenger Seat Schematics Passenger Seat Schematics
Connector End View Reference
Component Connector End Views A/C Compressor Clutch
Description and Operation
Lumbar Support Description and Operation (With Memory-A45) Lumbar Support (With Memory-A45)Lumbar Support Description and Operation (Without Memory-A45) Lumbar Support (Without Memory-A45)
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Circuit/System Verification
1. Ignition ON, press and hold the appropriate seat back bolster adjuster switch in the UP direction. The lumbar/bolster pump should run and the seat back bolsters should inflate until the switch is released or the bladders are 100% inflated.
2. Press and hold the seat back bolster adjuster switch in the DOWN direction. The seat back bolster bladders should deflate until the switch is released.
3. Press and hold the seat cushion bolster adjuster switch in the UP direction. The lumbar/bolster pump should run and the seat cushion bolsters should inflate until the switch is released or the bladders are 100% inflated.
4. Press and hold the seat cushion bolster adjuster switch in the DOWN direction. The seat cushion bolster bladders should deflate until the switch is released.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the appropriate bolster adjuster switch.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal D and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
3. Ignition OFF, connect the harness connector at the bolster adjuster switch and disconnect the harness connector at the seat bolster adjuster valve.
4. Test for less than 5 ohms between the ground circuit terminal 1 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
5. Connect a test lamp between the signal circuit terminals listed below and ground:
* Seat back inflate signal terminal 2
* Seat back deflate signal terminal 3
* Seat cushion inflate signal terminal 4
* Seat cushion deflate signal terminal 5
6. Ignition ON, press and release the appropriate bolster adjuster switch. The test lamp should turn ON and OFF when changing between the commanded states.
• If the test lamp is always ON, test the signal circuit for a short to voltage. If the circuit tests normal, test or replace the bolster adjuster switch.
• If the test lamp is always OFF, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the bolster adjuster switch.
7. Ignition OFF, connect the harness connector at the seat bolster adjuster valve and disconnect the harness connector at the seat lumbar/bolster pump.
8. Test for less than 5 ohms between the ground circuit terminal 3 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
9. Connect a test lamp between the control circuit terminal 1 and ground.
10. Ignition ON, command the pump motor ON and OFF using either one of the bolster inflate switches. The test lamp should turn ON and OFF when changing between the commanded states.
• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the seat bolster adjuster valve.
• If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the seat bolster adjuster valve.
11. If all circuits test normal, test or replace the seat lumbar/bolster pump.
Component Testing
Seat Back or Cushion Bolster Adjuster Switch
1. Ignition OFF, disconnect the harness connector at the appropriate bolster adjuster switch.
2. Test for infinite resistance between the B+ terminal D and each signal terminal with the switch in the open position.
• If not the specified value, replace the bolster adjuster switch.
3. Test for less than 1 ohms between the B+ terminal D and each signal terminal with the appropriate switch in the closed position.
• If greater than the specified range, replace the bolster adjuster switch.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Driver Seat Lumbar Control Switch Replacement Service and Repair
* Passenger Seat Lumbar Control Switch Replacement Service and Repair
* Front Seat Lumbar Support Bladder Replacement (W2E) Service and Repair
* Driver or Passenger Seat Cushion Air Pump Replacement (W2E) Driver or Passenger Seat Cushion Air Pump Replacement (W2E)