Part 2

Circuit/System Testing

Driver Window Motor Malfunction

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the M74D Window Motor-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 2 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 M74D Window Motor-Driver.

• If the test lamp illuminates

5. Test for 5-10 V between the serial data circuit terminal 4 and ground

• If less than 5 V

1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.

2. Test for infinite resistance between the serial data 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 ohms in the serial data circuit end to end.

• If 2 ohms or greater, repair the open/high resistance on the circuit.

• If less than 2 ohms, replace the K9 Body Control Module.

• If greater than 10 V

1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module, ignition ON.

2. 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

6. Replace the M74D Window Motor-Driver.

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 11 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 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 signal circuit terminal 8 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

5. Install a 3 A fused jumper wire between the signal circuit terminal 8 and the ground circuit terminal 11.

6. Verify the scan tool Driver Window Main Control Down Switch parameter is Active

• If not Active

1. Ignition OFF, disconnect the harness connector at the M74D Window Motor-Driver, ignition ON.

2. Test for less than 1 V between the signal circuit terminal 8 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 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

7. 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 signal circuit terminal 9 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

8. Install a 3 A fused jumper wire between the signal circuit terminal 9 and the ground circuit terminal 11.

9. Verify the scan tool Driver Window Main Control Up Switch parameter is Active

• If not Active

1. Ignition OFF, disconnect the harness connector at the M74D Window Motor-Driver, ignition ON.

2. Test for less than 1 V between the signal circuit terminal 9 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 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

10. Verify the scan tool Driver Window Main Control Express Switch parameter is Inactive.

• If not Inactive