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Circuit/System Testing

WARNING: This page is about a different car, the 2010 Chevrolet Camaro. However, it is still accessible from the selected car via links, so may be relevant.

Window Motor Malfunction

  1. Ignition OFF for, disconnect the harness connector at the appropriate M74 window motor.
  2. After 10 minutes, test for less than 10 Ω between the ground circuit terminal 1 and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 2 and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  4. Test for 5 - 10 V between the serial data circuit terminal 4 and ground.
    • If greater than the specified range, test the serial data circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.
    • If less than the specified range, test the serial data circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
  5. If all circuits test normal, replace the M74 window motor.

Driver Window Switch Malfunction

  1. Ignition OFF, disconnect the harness connector at the S79D window switch-driver.
  2. After 10 minutes, test for less than 10 Ω between the ground circuit terminal 1 and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify that the scan tool Driver Window Main Control Down Switch parameter is Inactive.
    • If not the specified value, test the signal circuit terminal 3 for a short to ground. If the circuit tests normal, replace the M74D window motor-driver.
  4. Connect a 3 A fused jumper wire between the signal circuit terminal 3 and ground. Verify that the scan tool Driver Window Main Control Down Switch parameter is Active.
    • If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the M74D window motor-driver.
  5. Verify that the scan tool Driver Window Main Control Up Switch parameter is Inactive.
    • If not the specified value, test the signal circuit terminal 5 for a short to ground. If the circuit tests normal, replace the M74D window motor-driver.
  6. Connect a 3 A fused jumper wire between the signal circuit terminal 5 and ground. Verify that the scan tool Driver Window Main Control Up Switch parameter is Active.
    • If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the M74D window motor-driver.
  7. Verify the scan tool Driver Window Main Control Express Switch parameter is Inactive.
    • If not the specified value, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the M74 driver window motor.
  8. Connect a 3 A fused jumper wire between the signal circuit terminal 2 and ground, verify the scan tool Driver Window Main Control Express Switch parameter is Active.
    • If not the specified value, test the signal circuit terminal for a short to voltage or an open/high resistance. If the circuit tests normal, replace the M74 driver window motor.
  9. If all circuits test normal, replace the S79D window switch-driver.

Passenger Window Switch Malfunction

  1. Ignition OFF, disconnect the harness connector at the S79P window switch-passenger.
  2. After 10 minutes, test for less than 10 Ω between the ground circuit terminal 1 and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Disconnect the harness connector at the S79D window switch-driver.
  4. Ignition ON, verify that the scan tool Passenger Window Switch at Door parameter is Inactive.
    • If the value is Up, test the signal circuit terminal 8 for a short to ground. If the circuit tests normal, test or replace the M74P window motor-passenger.
    • If the value is Down, test the signal circuit terminal 7 for a short to ground. If the circuit tests normal, test or replace the M74P window motor-passenger.
    • If the value is Express, test the signal circuit terminal 6 for a short to ground. If the circuit tests normal, test or replace the M74P window motor-passenger.
  5. Connect a 3 A fused jumper wire between the signal circuit terminal 8 and ground, verify that the scan tool Passenger Window Switch at Door parameter is Up.
    • If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the M74P window motor-passenger.
  6. Connect a 3 A fused jumper wire between the signal circuit terminal 7 and ground, verify that the scan tool Passenger Window Switch at Door parameter is Down.
    • If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the M74P window motor-passenger.
  7. Connect a 3 A fused jumper wire between the signal circuit terminal 6 and ground, verify that the scan tool Passenger Window Switch at Door parameter is Express.
    • If not the specified value, test the signal circuit terminal for a short to voltage or an open/high resistance. If the circuit tests normal, replace the M74 passenger window motor.
  8. Ignition OFF, connect the harness connector at the S79D window switch-driver.
  9. Ignition ON, observe the scan tool Passenger Window Switch at Door parameter while using the right front switch on the S79D window switch-driver. The parameters should change from Inactive to Up, Down and Express.
    • If the values do not change, test or replace the S79D window switch-driver.
  10. If all circuits test normal, test or replace the S79P window switch-passenger.
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