LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Cadillac >> 2015 >> XTS Base >> Repair and Diagnosis (Single Page) >> Steering >> Steering Wheel And Steering Column >> Diagnostic Information and Procedures >> DTC B285A: Steering Column Position Module >> Circuit/System Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit/System Testing

Switch Malfunction

  1. Ignition OFF, disconnect the harness connector at the S71 Steering Column Tilt and Telescope Switch. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 10 Ω between the low reference circuit terminal G and ground.
    • If 10 Ω or greater 
    1. Ignition OFF.
    2. 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, replace the K99 Steering Column Position Control Module.
    • If less than 10 Ω 
  3. Ignition ON.
  4. Test for B+ between the signal circuit terminals listed below and ground:
    • Terminal A
    • Terminal F
    • Terminal C
    • Terminal B
    • If less than B+ 
    1. Ignition OFF, disconnect the X4 harness connector at the K99 Steering Column Control Module.
    2. Test for infinite resistance between the signal 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 signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K99 Steering Column Position Control Module.
    • If B+ 
  5. Ignition OFF, disconnect the X4 harness connector at the K99 Steering Column Position Control Module. It may take up to 2 min for all vehicle systems to power down.
  6. Ignition ON.
  7. Test for less than 1 v between the signal circuit terminals listed below and ground:
    • Terminal 2
    • Terminal 3
    • Terminal 4
    • Terminal 5
    • If greater than 1 V 

      Repair the short to voltage on the circuit

    • If less than 1 V 
  8. Ignition OFF, connect the X4 harness connector at the K99 Steering Column Position Control Module. It may take up to 2 min for all vehicle systems to power down.
  9. Ignition ON.
  10. NOTE:

    When performing the following test, make sure that the steering column is not already in the position the test is attempting to produce.

  11. Install a 3 A fused jumper wire between the signal circuits listed below and the ground circuit terminal G. Verify the steering column telescopes FORWARD and REVERSE to the soft stop.
    • Terminal A
    • Terminal F
    • If the M65 Steering Column Telescope Motor does not operate 
    1. Ignition OFF, disconnect the X2 harness connector at the K99 Steering Column Position Control Module.
    2. Test for 1-2.5 Ω between terminal 1 and terminal 2.
      • If not within the specified range, replace the M65 Steering Column Telescope Motor.
      • If within the specified range, replace the K99 Steering Column Position Control Module.
    • If the M65 Steering Column Telescope Motor operates 
  12. NOTE:

    When performing the following test, make sure that the steering column is not already in the position the test is attempting to produce.

  13. Install a 3 A fused jumper wire between the signal circuits listed below and the ground circuit terminal G. Verify the steering column telescopes FORWARD and REVERSE to the soft stop.
    • Terminal B
    • Terminal C
    • If the M68 Steering Column Tilt Motor does not operate 
    1. Ignition OFF, disconnect the X1 harness connector at the K99 Steering Column Position Control Module.
    2. Test for 1-2.5 Ω between terminal 1 and terminal 2.
      • If not within the specified range, replace the M68 Steering Column Tilt Motor.
      • If within the specified range, replace the K99 Steering Column Position Control Module.
    • If the M68 Steering Column Tilt Motor operates 
  14. Test or replace the S71 Steering Column Tilt and Telescope Switch.

Tilt Motor Malfunction

  1. Ignition OFF, disconnect the X1 harness connector at the K99 Steering Column Position Control Module, ignition ON.
  2. Test for less than 1 V between each K99 Steering Column Position Control Module harness connector terminals listed below and ground.
    • Steering Column Tilt Motor Down Control - terminal 1
    • Steering Column Tilt Motor Up Control - terminal 2
    • Steering Column Tilt Motor Signal - terminal 4
    • If 1 V or greater 

      Repair the short to voltage on the circuit.

    • If less than 1 V 
  3. Ignition OFF.
  4. Test for infinite resistance between each K99 Steering Column Position Control Module harness connector terminals listed below and ground.
    • Steering Column Tilt Motor Down Control - terminal 1
    • Steering Column Tilt Motor Up Control - terminal 2
    • Steering Column Tilt Motor Signal - terminal 4
    • If less than infinite resistance 

      Repair the short to ground on the circuit.

    • If Infinite resistance 
  5. Replace the M68 Steering Column Tilt Motor.

Telescope Motor Malfunction

  1. Ignition OFF, disconnect the X2 harness connector at the K99 Steering Column Position Control Module, ignition ON.
  2. Test for less than 1 V between each K99 Steering Column Position Control Module harness connector terminals listed below and ground.
    • Steering Column Telescope Motor Forward - terminal 1
    • Steering Column Telescope Motor Rearward - terminal 2
    • Steering Column Telescope Motor Signal - terminal 4
    • If 1 V or greater 

      Repair the short to voltage on the circuit.

    • If less than 1 V 
  3. Ignition OFF.
  4. Test for infinite resistance between each K99 Steering Column Position Control Module harness connector terminals listed below and ground.
    • Steering Column Telescope Motor Forward - terminal 1
    • Steering Column Telescope Motor Rearward - terminal 2
    • Steering Column Telescope Motor Signal - terminal 4
    • If less than infinite resistance 

      Repair the short to ground on the circuit.

    • If Infinite resistance 
  5. Replace the M65 Steering Column Telescope Motor.