Battery voltage is supplied at all times through the PWR LUMBAR LH/RH 40A fuse located in the I/P fuse block to the driver and passenger seat pump/control modules and lumbar switches. When either the upper or lower lumbar switch is pressed to inflate the lumbar support, battery voltage is applied through the switch contacts and the lumbar inflate control circuit to the lumbar pump/control module. In response to this signal, the module energizes it's internal inflate relay and the pump motor runs to inflate the appropriate lumbar support bladder until the switch is released. When the lumbar switch is pressed to deflate the lumbar support, battery voltage is applied through the switch contacts and the lumbar deflate control circuit to the lumbar pump/control module. The module energizes it's internal deflate relay and air is released from the bladder until the switch is released. Ground for the driver seat pump is supplied at ground G301 and the passenger seat pump is supplied at ground G302.

Schematic Reference

Connector End View Reference

Component Connector End Views

Description and Operation

Memory Seats Description and Operation

Electrical Information Reference

1. Ignition ON, press the appropriate seat upper lumbar INFLATE adjuster switch. The lumbar pump motor should run and the upper lumbar support should inflate and stay inflated until the deflate switch is pressed.
2. Press the upper lumbar DEFLATE adjuster switch to the deflate position. The upper lumbar support should deflate.
3. Press the lower lumbar INFLATE adjuster switch. The lumbar pump motor should run and the lower lumbar support should inflate and stay inflated until the deflate switch is pressed.
4. Press the lower lumbar DEFLATE adjuster switch. The lower lumbar support should deflate.

1. Ignition OFF, disconnect the harness connector at the appropriate seat upper or lower lumbar 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 lumbar adjuster switch and disconnect the harness connector at the seat lumbar pump/control module.
4. Test for less than 5.0 Ω between the ground circuit terminal A and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

5. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal K and ground.

⇒	If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.

6. Connect a test lamp between the appropriate inflate control circuit terminal listed below and ground:

•	Upper lumbar inflate control terminal G

•	Lower lumbar inflate control terminal H

7. Ignition ON, press and release the appropriate lumbar inflate switch. The test lamp should turn ON and OFF as the switch is pressed and released.

⇒	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 lumbar adjuster switch.

⇒	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, replace the lumbar adjuster switch.

8. Connect a test lamp between the appropriate deflate control circuit listed below and ground:

•	Upper lumbar deflate control terminal D

•	Lower lumbar deflate control terminal C

9. Press and release the appropriate lumbar deflate switch. The test lamp should turn ON and OFF as the switch is pressed and released.

⇒	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 lumbar adjuster switch.

⇒	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, replace the lumbar adjuster switch.

10. If all circuits test normal, replace the lumbar pump/control module.

Driver Seat Lumbar Switch

1. Ignition OFF, disconnect the harness connector at the appropriate lumbar switch.
2. Test for infinite resistance between the B+ circuit terminal D and the switch terminals listed below with the switch in the open position.

•	Lumbar inflate terminal E

•	Lumbar deflate terminal B

⇒	If not the specified value, replace the lumbar switch.

3. Test for less than 1 Ω between the control terminal E and the B+ terminal 5 with the inflate switch in the closed position.

⇒	If greater than the specified range, replace the lumbar switch.

4. Test for less than 1 Ω between the control terminal B and the B+ terminal 5 with the deflate switch in the closed position.

⇒	If greater than the specified range, replace the lumbar switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.