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