Circuit/System Testing

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 ohms between the ground circuit terminal 1 and ground.
   • If 10 ohms or greater 
   1. Ignition OFF.
   2. Test for less than 2 ohms in the ground circuit end to end.
      • If 2 ohms or greater, repair the open/high resistance in the circuit.
      • If less than 2 ohms, repair the open/high resistance in the ground connection.
   • If less than 10 ohms 
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 ohms in the B+ circuit end to end.
      • If 2 ohms or greater, repair the open/high resistance in the circuit.
      • If less than 2 ohms, 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 3A 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 3A fused jumper wire, disconnect the harness connector at the M74D Window Motor-Driver, ignition ON.
   2. Test for less than 1V between the S79D Window Switch-Driver signal circuit terminal 3 and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V
   3. Test for less than 2 ohms in the signal circuit end to end.
      • If 2 ohms or greater, repair the open/high resistance in the circuit.
      • If less than 2 ohms, replace the M74D Window Motor-Driver.
   • If Active 
8. Verify the scan tool Driver Window Main Control Up 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 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 3A 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 1V between the S79D Window Switch-Driver signal circuit 6 and ground.
       • If 1V or greater, repair the short to voltage on the circuit.
       • If less than 1V
    3. Test for less than 2 ohms in the signal circuit end to end.
       • If 2 ohms or greater, repair the open/high resistance in the circuit.
       • If less than 2 ohms, 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 3A 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 1V between the S79D Window Switch-Driver signal circuit 2 and ground.
       • If 1V or greater, repair the short to voltage on the circuit.
       • If less than 1V
    3. Test for less than 2 ohms in the signal circuit end to end.
       • If 2 ohms or greater, repair the open/high resistance in the circuit.
       • If less than 2 ohms, replace the M74D Window Motor-Driver.
    • If Active 
14. Test or replace the S79D Window Switch-Driver.

Passenger Window Switch Malfunction

1. Ignition OFF, and all vehicle systems OFF, disconnect the harness connector at the S79P Window Switch-Passenger. It may take up to 2 minutes for all vehicle systems to power down
2. Test for less than 10 ohms between the ground circuit terminal 1 and ground.
   • If 10 ohms or greater 
   1. Ignition OFF.
   2. Test for less than 2 ohms in the ground circuit end to end.
      • If 2 ohms or greater, repair the open/high resistance in the circuit.
      • If less than 2 ohms, repair the open/high resistance in the ground connection.
   • If less than 10 ohms 
3. Ignition ON.
4. Verify the scan tool Passenger Window Switch at Door parameter is Inactive.
   • If not Inactive 
   1. Ignition OFF, disconnect the harness connector at the M74P Window Motor-Passenger
   2. Test for infinite resistance between the signal circuit terminal listed below and ground:
      • S79P Window Switch-Passenger - signal circuit terminal 7
      • S79P Window Switch-Passenger - signal circuit terminal 8
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the M74P Window Motor-Passenger.
   • If Inactive 
5. Install a 3A fused jumper wire between the signal circuit terminal 8 and ground:
6. Verify the scan tool Passenger Window Switch at Door parameter is Up
   • If not Up 
   1. Ignition OFF, remove the fused jumper wire, disconnect the harness connector at the M74P Window Motor-Passenger, ignition ON.
   2. Test for less than 1V between the S79P Window Switch-Passenger signal circuit terminal 8 and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V
   3. Ignition OFF, test for less than 2 ohms in the signal circuit end to end.
      • If 2 ohms or greater, repair the open/high resistance in the circuit.
      • If less than 2 ohms, replace the M74P Window Motor-Passenger.
   • If Up 
7. Install a 3A fused jumper wire between the signal circuit terminal 7 and ground.
8. Verify the scan tool Passenger Window Switch at Door parameter is Down
   • If not Down 
   1. Ignition OFF, remove the fused jumper wire, disconnect the harness connector at the M74P Window Motor-Passenger, ignition ON.
   2. Test for less than 1V between the S79P Window Switch-Passenger signal circuit terminal 7 and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V
   3. Ignition OFF, test for less than 2 ohms in the signal circuit end to end.
      • If 2 ohms or greater, repair the open/high resistance in the circuit.
      • If less than 2 ohms, replace the M74P Window Motor-Passenger.
   • If Down 
9. Test for greater than 10V between the signal circuit terminal 6 and ground
   • If less than 10V 
   1. Ignition OFF, disconnect the harness connector at the M74P Window Motor-Passenger.
   2. Test for infinite resistance between the S79P Window Switch-Passenger signal circuit 6 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
   3. Test for less than 2 ohms in the signal circuit end to end.
      • If 2 ohms or greater, repair the open/high resistance on the circuit.
      • If less than 2 ohms, replace the M74P Window Motor-Passenger.
   • If greater than 10V 
10. Test or replace the S79P Window Switch-Passenger.