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Home >> Chevrolet >> 2020 >> Malibu LS >> Repair and Diagnosis >> External Pages >> Different car >> Section 127 (Sunroof) >> Diagnostic Information and Procedures >> Power Sunshade Malfunction (C3U) >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.

Sunshade Switch Malfunction

    NOTE:

    Because of the accessibility of the sunshadef switch, perform the component testing before beginning the Circuit/System Testing.

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the A98 Front Overhead Console Assembly. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 10 Ω between the low reference circuit terminal 4 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF/Vehicle OFF, disconnect the harness connector at the M69 Sunroof Motor.
    2. Test for less than 2 Ω in the low reference circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, test or replace the M69 Sunroof Motor.
    • Go to next step: If less than 10 Ω 
  3. Ignition ON/Vehicle in Service Mode.
  4. Test for 4.8 - 5.2 V between the 5 V reference circuit terminal 10 and ground.
    • If less than 4.8 V 
    1. Ignition OFF/Vehicle OFF, disconnect the harness connector at the M69 Sunroof Motor.
    2. Test for infinite resistance between the 5 V reference circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the 5 V reference circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the M69 Sunroof Motor.
    • If greater than 5.2 V 
    1. Ignition OFF/Vehicle OFF, disconnect the harness connector at the M69 Sunroof Motor, ignition ON/vehicle in Service Mode.
    2. Test for less than 1 V between the 5 V reference circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the M69 Sunroof Motor.
    • Go to next step: If between 4.8 - 5.2 V 
  5. Test or replace the A98 Front Overhead Console Assembly.

Power Sunshade Malfunction

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the M81 Sunroof Sunshade Motor. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 10 Ω between the low reference circuit terminal 4 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF/Vehicle OFF.
    2. 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.
    • Go to next step: If less than 10 Ω 
  3. Ignition ON/Vehicle in Service Mode.
  4. Test for greater than 11 V between the 12 V reference circuit terminal 6 and ground.
    • If 11 V or less 
    1. Ignition OFF/Vehicle OFF, disconnect the harness connector at the M69 Sunroof Motor.
    2. Test for infinite resistance between the 12 V reference circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the 12 V reference circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the M69 Sunroof Motor.
    • Go to next step: If greater than 11 V 
  5. Test for 4.8 - 5.2 V between the Position Sensor Signal 1 circuit terminal 3 and ground.
    • If less than 4.8 V 
    1. Ignition OFF/Vehicle OFF, disconnect the harness connector at the M69 Sunroof Motor.
    2. Test for infinite resistance between the Position Sensor Signal 1 circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the Position Sensor Signal 1 circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the M69 Sunroof Motor.
    • If greater than 5.2 V 
    1. Ignition OFF/Vehicle OFF, disconnect the harness connector at the M69 Sunroof Motor, ignition ON/vehicle in Service Mode.
    2. Test for less than 1 V between the Position Sensor Signal 1 circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the M69 Sunroof Motor.
    • Go to next step: If between 4.8 - 5.2 V 
  6. Test for 4.8 - 5.2 V between the Position Sensor Signal 2 circuit terminal 5 and ground.
    • If less than 4.8 V 
    1. Ignition OFF/Vehicle OFF, disconnect the harness connector at the M69 Sunroof Motor.
    2. Test for infinite resistance between the Position Sensor Signal 2 circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the Position Sensor Signal 2 circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the M69 Sunroof Motor.
    • If greater than 5.2 V 
    1. Ignition OFF/Vehicle OFF, disconnect the harness connector at the M69 Sunroof Motor, ignition ON/vehicle in Service Mode.
    2. Test for less than 1 V between the Position Sensor Signal 2 circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the M69 Sunroof Motor.
    • Go to next step: If between 4.8 - 5.2 V 
  7. Ignition OFF/Vehicle OFF, disconnect the harness connector at the M69 Sunroof Motor. It may take up to 2 min for all vehicle systems to power down.
  8. Test for less than 10 Ω between the control circuit terminal 2 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF/Vehicle OFF, disconnect the harness connector at the M69 Sunroof Motor.
    2. Test for less than 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the M69 Sunroof Motor.
    • Go to next step: If less than 10 Ω 
  9. Test for less than 10 Ω between the control circuit terminal 3 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF/Vehicle OFF, disconnect the harness connector at the M69 Sunroof Motor.
    2. Test for less than 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the M69 Sunroof Motor.
    • Go to next step: If less than 10 Ω 
  10. Connect a test lamp between control circuit terminal 1 and control circuit terminal 2, ignition ON/vehicle in Service Mode.
  11. Verify the test lamp turns ON and OFF when commanding the OPEN and CLOSE on the A98 Front Overhead Console Assembly.
    • If the test lamp remains OFF when commanding the OPEN and CLOSE on the A98 Front Overhead Console Assembly. 
    1. Ignition OFF/Vehicle OFF, remove the test lamp, disconnect the harness connector at the M69 Sunroof Motor.
    2. Test for infinite resistance between each control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the M69 Sunroof Motor.
    • If the test lamp turns ON when commanding the OPEN and CLOSE on the A98 Front Overhead Console Assembly. 
    1. Ignition OFF/Vehicle OFF, remove the test lamp, disconnect the harness connector at the M69 Sunroof Motor, ignition ON/vehicle in Service Mode.
    2. Test for less than 1 V between each control circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the M69 Sunroof Motor.
    • Go to next step: If the test lamp turns ON and Off when commanding the OPEN and CLOSE on the A98 Front Overhead Console Assembly. 
  12. Replace the M69 Sunroof Motor.
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