LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Cadillac >> 2016 >> CTS Base, AWD >> Repair and Diagnosis >> Body & Frame >> Windows >> Fixed And MOVEABLE Window System >> Diagnostic Information and Procedures >> Power Windows Malfunction >> Circuit/System Testing >> Driver Window Switch Malfunction
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Driver Window Switch Malfunction

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S79D Window Switch-Driver. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 10 Ω between the ground circuit terminal 1 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, repair the open/high resistance in the ground connection.
    • If less than 10 Ω 
  3. Ignition ON.
  4. Verify a test lamp illuminates between the B+ circuit terminal 4 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Ignition OFF.
    2. 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 does not illuminate and the circuit fuse is open 
    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, replace the S79D Window Switch-Driver.
    • If the test lamp illuminates 
  5. Verify the scan tool Driver Window Main Control Down Switch parameter is Inactive.
    • If not Inactive 
    1. Ignition OFF, disconnect the harness connector at the M74D Window Motor-Driver.
    2. Test for infinite resistance between the S79D Window Switch-Driver signal circuit terminal 3 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the M74D Window Motor-Driver.
    • If Inactive 
  6. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the ground circuit terminal 1.
  7. Verify the scan tool Driver Window Main Control Down Switch parameter is Active
    • If not Active 
    1. Ignition OFF, remove the 3 A fused jumper wire, disconnect the harness connector at the M74D Window Motor-Driver, ignition ON.
    2. Test for less than 1 V between the S79D Window Switch-Driver signal circuit terminal 3 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V
    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 M74D Window Motor-Driver.
    • If Active 
  8. Verify the scan tool Driver Window Main Control Up Switch parameter is Inactive.
    • If not Active 
    1. Ignition OFF, disconnect the harness connector at the M74D Window Motor-Driver.
    2. Test for infinite resistance between the S79D Window Switch-Driver signal circuit terminal 6 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the M74D Window Motor-Driver.
    • If Inactive 
  9. Install a 3 A fused jumper wire between the signal circuit terminal 6 and the ground circuit terminal 1.
  10. Verify the scan tool Driver Window Main Control Up Switch parameter is Active
    • If not Active 
    1. Ignition OFF, remove the 3A fused jumper wire, disconnect the harness connector at the M74D Window Motor-Driver, ignition ON.
    2. Test for less than 1 V between the S79D Window Switch-Driver signal circuit 6 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V
    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 M74D Window Motor-Driver.
    • If Active 
  11. Verify the scan tool Driver Window Main Control Express Switch parameter is Inactive.
    • If not Inactive 
    1. Ignition OFF, disconnect the harness connector at the M74D Window Motor-Driver.
    2. Test for infinite resistance between the S79D Window Switch-Driver signal circuit terminal 2 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the M74D Window Motor-Driver.
    • If Inactive 
  12. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the ground circuit terminal 1.
  13. Verify the scan tool Driver Window Main Control Express Switch parameter is Active
    • If not Active 
    1. Ignition OFF, remove the 3A fused jumper wire, disconnect the harness connector at the M74D Window Motor-Driver, ignition ON.
    2. Test for less than 1 V between the S79D Window Switch-Driver signal circuit 2 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V
    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 M74D Window Motor-Driver.
    • If Active 
  14. Test or replace the S79D Window Switch-Driver.
scientia non olet · About LEMON Manuals