Circuit/System Testing

B3920 01 or B3920 02

Ignition OFF, disconnect the X3 harness connector at the seat memory control module listed below:
- K40D Seat Memory Control Module - Driver
- K40P Seat Memory Control Module - Passenger
Test for infinite resistance between each control circuit terminal listed below and ground:
- Front vertical motor up control terminal 3
- Front vertical motor down control terminal 4
- Rear vertical motor up control terminal 5
- Rear vertical motor down control terminal 6
- Horizontal motor forward control terminal 11
- Horizontal motor rearward control terminal 12
- Recline motor forward control terminal 1
- Recline motor rearward control terminal 2
- Lumbar up control terminal 7
- Lumbar down control terminal 8
- Lumbar forward control terminal 9
- Lumbar rearward control terminal 10
- If less than infinite resistance
  Repair the short to ground on the circuit.
- Go to next step: If infinite resistance
Ignition ON.
Test for less than 1 V between each control circuit terminal listed below and ground:
- Front vertical motor up control terminal 3
- Front vertical motor down control terminal 4
- Rear vertical motor up control terminal 5
- Rear vertical motor down control terminal 6
- Horizontal motor forward control terminal 11
- Horizontal motor rearward control terminal 12
- Recline motor forward control terminal 1
- Recline motor rearward control terminal 2
- Lumbar up control terminal 7
- Lumbar down control terminal 8
- Lumbar forward control terminal 9
- Lumbar rearward control terminal 10
- If 1 V or greater
  Repair the short to voltage on the circuit.
- Go to next step: If less than 1 V
Ignition OFF, disconnect the harness connector at the K104 Seat Lumbar Support Control Module.
Test for infinite resistance between each control circuit terminal listed below and ground.
- Upper lumbar motor control terminal 6
- Upper lumbar motor control terminal 7
- Lower lumbar motor control terminal 8
- Lower lumbar motor control terminal 4
- If less than infinite resistance
  Repair the short to ground on the circuit.
- Go to next step: If infinite resistance
Ignition ON.
Test for less than 1 V between each control circuit terminal listed below and ground.
- Upper lumbar motor control terminal 6
- Upper lumbar motor control terminal 7
- Lower lumbar motor control terminal 8
- Lower lumbar motor control terminal 4
- If 1 V or greater
  Repair the short to voltage on the circuit.
- Go to next step: If less than 1 V
Replace the K40 Seat Memory Control Module.

B3920 00 or B3920 0B

Ignition ON.
Clear the current and history DTC.
Determine which motor set this DTC by operating the seat and lumbar motors listed below one at a time in both directions. Check for the DTC to set between each motor test.
- M50 Seat Front Vertical Motor
- M55 Seat Rear Vertical Motor
- M51 Seat Horizontal Motor
- M56 Seat Recline Motor
- M53U Seat Lumbar Support Motor - Upper
- M53L Seat Lumbar Support Motor - Lower
Ignition OFF, disconnect the harness connector at the seat motor for which the DTC set, ignition ON.
Clear the DTC.
Verify that DTC B3920 00 or B3920 0B does not set while operating the seat motor adjuster switch in both directions.
- If DTC B3920 00 or B3920 0B sets
1. Test for infinite resistance between the appropriate control circuit terminals listed below:
  - All seat motors control circuit terminal 1 and control circuit terminal 5
  - Both lumbar motors control circuit terminal A and control circuit terminal B
  - If less than infinite resistance, repair the short between the circuits.
  - Go to next step: If infinite resistance
2. 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 seat motor.
- Go to next step: If DTC B3920 00 or B3920 0B does not set
Replace the seat motor.