Circuit/System Testing

Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate seat lumbar support switch listed below. It may take up to 2 min for all vehicle systems to power down.
- S65D Seat Lumbar Support Switch - Driver
- S65P Seat Lumbar Support Switch - Passenger
Test for less than 10 Ω between the ground circuit terminal H and ground.
- If 10 Ω or greater
1. Test for less than 2 Ω in the ground circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, repair the open/high resistance in the ground connection.
- If less than 10 Ω
Ignition ON.
Verify a test lamp illuminates between the B+ circuit terminal E and ground.
- If the test lamp does not illuminate
1. Ignition OFF.
2. Test for infinite resistance between the B+ circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance
3. Test for less than 2 Ω in the B+ circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
- If the test lamp illuminates
Ignition OFF, connect the harness connector at the S65 Seat Lumbar Support Switch and disconnect the harness connector at the M53 Seat Lumbar Support Motor.
Connect a test lamp between control circuit terminal A and control circuit terminal B, ignition ON.
Verify the test lamp turns ON when commanding the lumbar support Forward and Rearward using the S65 Seat Lumbar Support Switch.
- If the test lamp remains OFF during either of the commands
1. Ignition OFF, disconnect the harness connector at the S65 Seat Lumbar Support Switch.
2. Test for infinite resistance between each control circuit and ground.
  - If less than Infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance
3. Test for less than 2 Ω in each control circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, replace the S65 Seat Lumbar Support Switch.
- If the test lamp remains ON during either of the commands
1. Ignition OFF, disconnect the harness connector at the S65 Seat Lumbar Support Switch, ignition ON.
2. Test for less than 1 V between each control circuit and ground.
  - If 1 V or greater, repair the short to voltage on the circuit.
  - If less than 1 V, replace the S65 Seat Lumbar Support Switch.
- If the test lamp turns ON during each of the commands
Test or replace the M53 Seat Lumbar Support Motor.