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Home >> Cadillac >> 2018 >> CT6 Plug-In >> Repair and Diagnosis >> Body & Frame >> Seats >> Power Seat System >> Diagnostic Information and Procedures >> Lumbar Support Malfunction (With Seat Bolster Memory Control Module) >> Circuit/System Verification
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Circuit/System Verification

  1. Ignition ON/Vehicle in Service Mode.
  2. Verify that no DTCs are set.
    • Go to next step: If no DTCs are set 
  3. Select the appropriate scan tool control module listed below:
    • Seat Memory Control Module - Driver
    • Seat Memory Control Module - Passenger
    • Seat Memory Control Module - Left Rear
    • Seat Memory Control Module - Right Rear
  4. Verify the scan tool Seat Function Select Switch parameter changes between Inactive and UP or Down when operating the switch.
    • If the parameter does not change 

      Test or replace the S64 Seat Adjuster Switch.

    • Go to next step: If the parameter changes 
  5. Verify the scan tool Seat 4-Way Switch parameter changes between Inactive and UP/Down or Forward/Rearward when operating the 4-way switch in the up/down and forward/rearward directions.
    • If the parameter does not change 

      Test or replace the S64 Seat Adjuster Switch.

    • Go to next step: If the parameter changes 
  6. Verify the scan tool Seat Massage Switch parameter changes between Active and Inactive when pressing the seat massage switch.
    • If the parameter does not change 

      Test or replace the S64 Seat Adjuster Switch.

    • Go to next step: If the parameter changes 
  7. Verify that all K134 Seat Bolster Memory Control Module functions operate when being controlled by the S64 Seat Adjuster Switch.
    • If all K134 Seat Bolster Memory Control Module functions are inoperative 

      Perform the seat lumbar/bolster pump component test below.

    • If any but not all of the K134 Seat Bolster Memory Control Module functions is inoperative 
    1. Ignition ON/Vehicle in Service Mode.
    2. Test the integrity of the air hoses and bladders for the inoperative lumbar/bolster function.
      • If a fault is found with the air hoses or bladders, repair or replace as needed.
      • Go to next step: If the air hoses and bladders test normal.
    3. Replace the K134 Seat Bolster Memory Control Module.
    • Go to next step: If all K134 Seat Bolster Memory Control Module functions operate 
  8. All OK.