Circuit/System Testing
Driver Window Switch Malfunction
- 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.
- Test for less than 10 Ω between the ground circuit terminal 1 and ground.
- If 10 Ω or greater
- Ignition OFF.
- 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
- 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
- Ignition OFF.
- 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
- Ignition OFF.
- 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
- 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, replace the S79D window switch-driver
- If the test lamp illuminates
- Test for 5-10 V between the serial data circuit terminal 5 and ground
- If less than 5 V
- Ignition OFF, disconnect the harness connector at the K9 body control module.
- Test for infinite resistance between the serial data and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the serial data circuit end to end.
- If 2 Ω or greater, repair the open/high resistance on the circuit.
- If less than 2 Ω, replace the K9 body control module.
- If greater than 10 V
- Ignition OFF, disconnect the harness connector at the K9 body control module, ignition ON.
- Test for less than 1 V between the serial data signal circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K9 body control module.
- If between 5-10 V
- Test or replace the S79D window switch-driver.
Rear Power Window Inoperative
- Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate rear M74 window motor. It may take up to 2 minutes for all vehicle systems to power down.
- Test for less than 10 Ω between the ground circuit terminal 1 and ground.
- If 10 Ω or greater
- Ignition OFF.
- 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
- Ignition ON.
- Verify a test lamp illuminates between the B+ circuit terminal 2 and ground.
- If the test lamp does not illuminate and the circuit fuse is good
- Ignition OFF.
- 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
- Ignition OFF.
- 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
- 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, replace the rear M74 window motor.
- If the test lamp illuminates
- Test for 5-10 V between the serial data circuit terminal 4 and ground
- If less than 5 V
- Ignition OFF, disconnect the harness connector at the K9 body control module.
- Test for infinite resistance between the serial data and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the serial data circuit end to end.
- If 2 Ω or greater, repair the open/high resistance on the circuit.
- If less than 2 Ω, replace the K9 body control module.
- If greater than 10 V
- Ignition OFF, disconnect the harness connector at the K9 body control module, ignition ON.
- Test for less than 1 V between the serial data circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K9 body control module.
- If between 5-10 V
- Replace the rear M74 window motor.