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Home >> GMC >> 2018 >> Acadia Denali, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 272 (Power Seat System) >> Diagnostic Information and Procedures >> DTC B3920: Seat Motors Group 1 Common Circuit (Without W2E) >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2017 Cadillac ATS. However, it is still accessible from the selected car via links, so may be relevant.

B3920 01 or B3920 02

  1. Ignition OFF, disconnect the X3 and X4 harness connectors at the K40D Seat Memory Control Module - Driver.
  2. Test for infinite resistance between each control circuit terminal listed below and ground:
    • Driver seat front vertical motor up control terminal 3 X3
    • Driver seat front vertical motor down control terminal 4 X3
    • Driver seat rear vertical motor up control terminal 5 X3
    • Driver seat rear vertical motor down control terminal 6 X3
    • Driver seat horizontal motor forward control terminal 11 X3
    • Driver seat horizontal motor rearward control terminal 12 X3
    • Driver seat recline motor forward control terminal 1 X3
    • Driver seat recline motor rearward control terminal 2 X3
    • Passenger seat horizontal motor forward control terminal 4 X4
    • Passenger seat horizontal motor rearward control terminal 3 X4
    • If less than infinite resistance 

      Repair the short to ground on the circuit.

    • If infinite resistance 
  3. Ignition OFF, disconnect the harness connector at the appropriate component listed below:
    • G31D Seat Lumbar/Bolster Pump - Driver
    • A14D Seat Lumbar Support Pump - Driver
  4. Test for infinite resistance between each control circuit terminal listed below and ground:
    • Driver power seat side bolster inflate control terminal 1 - with AHE
    • Driver power seat side bolster deflate control terminal 3 - with AHE
    • Driver power seat lumbar motor forward control terminal 5
    • Driver power seat lumbar motor rearward control terminal 2
    • If less than infinite resistance 

      Repair the short to ground on the circuit.

    • If infinite resistance 
  5. Ignition ON.
  6. Test for less than 1 V between each control circuit terminal listed below and ground:
    • Driver seat front vertical motor up control terminal 3 X3
    • Driver seat front vertical motor down control terminal 4 X3
    • Driver seat rear vertical motor up control terminal 5 X3
    • Driver seat rear vertical motor down control terminal 6 X3
    • Driver seat horizontal motor forward control terminal 11 X3
    • Driver seat horizontal motor rearward control terminal 12 X3
    • Driver seat recline motor forward control terminal 1 X3
    • Driver seat recline motor rearward control terminal 2 X3
    • Passenger seat horizontal motor forward control terminal 4 X4
    • Passenger seat horizontal motor rearward control terminal 3 X4
    • If 1 V or greater 

      Repair the short to voltage on the circuit.

    • If less than 1 V 
  7. Ignition OFF, disconnect the harness connector at the appropriate component listed below:
    • G31D Seat Lumbar/Bolster Pump - Driver
    • A14D Seat Lumbar Support Pump - Driver
  8. Test for less than 1 V between each control circuit terminal listed below and ground:
    • Driver power seat side bolster inflate control terminal 1 - with AHE
    • Driver power seat side bolster deflate control terminal 3 - with AHE
    • Driver power seat lumbar motor forward control terminal 5
    • Driver power seat lumbar motor rearward control terminal 2
    • If 1 V or greater 

      Repair the short to voltage on the circuit.

    • If less than 1 V 
  9. Replace the K40D Seat Memory Control Module - Driver.

B3920 00 or B3920 0B

  1. Ignition ON.
  2. Clear the current and history DTC.
  3. Determine which motor set this DTC by operating the driver and passenger seat motors listed below one at a time in both directions. Check for the DTC to set between each motor test.
    • M50D Seat Front Vertical Motor - Driver
    • M55D Seat Rear Vertical Motor - Driver
    • M51D Seat Horizontal Motor - Driver
    • M56D Seat Recline Motor - Driver
    • G31D Seat Lumbar/Bolster Pump - Driver with - AHE
    • A14D Seat Lumbar Support Pump - Driver - without AHE
    • M51P Seat Horizontal Motor - Passenger
  4. Ignition OFF, disconnect the harness connector at the seat motor for which the DTC set, ignition ON.
  5. Clear the DTC.
  6. 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. Ignition OFF.
    2. Test for infinite resistance between the appropriate control circuit terminals listed below:
      • All driver seat motors and passenger seat horizontal motor control circuit terminal 1 and control circuit terminal 3
      • Driver seat lumbar horizontal control circuit terminal 2 and control circuit terminal 5
      • Driver seat lumbar/bolster pump control circuit terminal 1 and control circuit terminal 3
      • If less than infinite resistance, repair the short between the circuits.
      • 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, test or replace the seat motor.
    • If DTC B3920 00 or B3920 0B does not set 
  7. Test or replace the seat motor.
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