LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2020 >> Malibu LS >> Repair and Diagnosis >> External Pages >> Different car >> Section 95 (Hybrid/EV Energy Storage System) >> Diagnostic Information and Procedures >> DTC P0C78 or P3061 >> 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.

Contactor Diagnosis

    WARNING:

    Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.

    The High Voltage Disabling procedure includes the following steps:

    • Identify how to disable high voltage.
    • Identify how to test for the presence of high voltage.
    • Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.

    Before working on any high voltage system, be sure to wear the following Personal Protection Equipment:

    • Safety glasses with appropriate side shields when within 15 meters (50 feet) of the vehicle, either indoors or outdoors.
    • Certified and up-to-date Class "0" Insulation gloves rated at 1000V with leather protectors.
      • Visually and functionally inspect the gloves before use.
      • Wear the Insulation gloves with leather protectors at all times when working with the high voltage battery assembly, whether the system is energized or not.

    Failure to follow the procedures may result in serious injury or death.

  1. Vehicle OFF, disable the high voltage at the A4 Hybrid/EV Battery Pack. Refer to High Voltage Disabling .
  2. Remove the A4 hybrid/EV battery pack cover. Refer to High Voltage Battery Cover Replacement .
  3. Disconnect the X4 harness connector at the A28 Hybrid/EV Battery Contactor Assembly.
  4. Test for less than 10 Ω between the ground circuit terminal 4, X4 and ground.
    • If more than 10 Ω 
  5. 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 
    6. NOTE:

    Connecting the 12V battery with the S15 manual service disconnect removed may set other DTCs.

  6. Connect the 12V battery. Vehicle in Service Mode.
  7. Verify that a test lamp does not illuminate between each A28 Hybrid/EV Battery Contactor Assembly harness connector control circuit terminals listed below and ground:
    • Terminal 1 X4
    • Terminal 2 X4
    • Terminal 3 X4
    • If the test lamp illuminates on any circuit 
    1. Vehicle OFF, disconnect the X4 harness connector at the K114B Hybrid Powertrain Control Module 2. Vehicle in Service Mode.
    2. Test for less than 1 V between the control circuit terminals listed below and ground:
      • Terminal 1 X4
      • Terminal 2 X4
      • Terminal 3 X4
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K114B Hybrid Powertrain Control Module 2.
    • Go to next step: If the test lamp does not illuminate on all circuits 
  8. Vehicle OFF, disconnect the X4 harness connector at the K114B Hybrid Powertrain Control Module 2.
  9. Test for infinite resistance between each A28 Hybrid/EV Battery Contactor Assembly harness connector control circuit terminals listed below and ground:
    • Terminal 1 X4
    • Terminal 2 X4
    • Terminal 3 X4
    • If less than infinite resistance on either circuit 

      Repair the short to ground on the circuit.

    • Go to next step: If infinite resistance on both circuits 
  10. Test for less than 2 Ω between the harness connector terminals listed below:
    • Terminal 1 X4 at the A28 Hybrid/EV Battery Contactor Assembly and terminal 3 X4 at the K114B Hybrid Powertrain Control Module 2
    • Terminal 2 X4 at the A28 Hybrid/EV Battery Contactor Assembly and terminal 2 X4 at the K114B Hybrid Powertrain Control Module 2
    • Terminal 3 X4 at the A28 Hybrid/EV Battery Contactor Assembly and terminal 1 X4 at the K114B Hybrid Powertrain Control Module 2
    • If 2 Ω or greater on any circuit 

      Repair the open/high resistance in the circuit.

    • Go to next step: If less than 2 Ω on all circuits 
  11. Replace the A28 Hybrid/EV Battery Contactor Assembly.
  12. Verify that DTC P0C78 or P3061 does not set while operating the vehicle within the Conditions for Running the DTC.
    • If DTC P0C78 or P3061 sets 

      Replace the K114B Hybrid Powertrain Control Module 2.

    • Go to next step: If DTC P0C78 or P3061 does not set 
  13. All OK.

System Bus Diagnosis

    WARNING:

    Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.

    The High Voltage Disabling procedure includes the following steps:

    • Identify how to disable high voltage.
    • Identify how to test for the presence of high voltage.
    • Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.

    Before working on any high voltage system, be sure to wear the following Personal Protection Equipment:

    • Safety glasses with appropriate side shields when within 15 meters (50 feet) of the vehicle, either indoors or outdoors.
    • Certified and up-to-date Class "0" Insulation gloves rated at 1000V with leather protectors.
      • Visually and functionally inspect the gloves before use.
      • Wear the Insulation gloves with leather protectors at all times when working with the high voltage battery assembly, whether the system is energized or not.

    Failure to follow the procedures may result in serious injury or death.

  1. Vehicle OFF, disable the high voltage at the G1 A/C Compressor, T6 Power Inverter Module, K1 14V Power Module and the A4 Hybrid/EV Battery Pack. Refer to High Voltage Disabling .
    2. NOTE:

    The resistance results may vary greatly based upon both the duration of meter connection and the polarity of the test leads.

  2. Test for greater than 1 K Ω between the T6 Power Inverter Module high voltage connector X5 terminals A and B.
    • If less than the specified range 
    1. Replace the T6 power invert module.
    2. Verify that DTC P0C78 or P3061 does not set while operating the vehicle within the Conditions for Running the DTC.
      • If the DTC sets, replace the A28 hybrid/EV battery contactor assembly
      • If the DTC does not set, All OK.
    • Go to next step: If greater than the specified range 
    3. NOTE:

    The resistance results may vary greatly based upon both the duration of meter connection and the polarity of the test leads.

  3. Test for greater than 1 K Ω between the G1 A/C Compressor high voltage connector terminals A and B.
    • If less than the specified range 
    1. Replace the G1 A/C Compressor.
    2. Verify that DTC P0C78 or P3061 does not set while operating the vehicle within the Conditions for Running the DTC.
      • If the DTC sets, replace the A28 hybrid/EV battery contactor assembly
      • If the DTC does not set, All OK.
    • Go to next step: If greater than the specified range 
    4. NOTE:

    The resistance results may vary greatly based upon both the duration of meter connection and the polarity of the test leads.

  4. Test for greater than 1 K Ω between the K1 14V Power Module high voltage connector terminals A and B, X4.
    • If less than the specified range 
    1. Replace the K1 14V Power Module.
    2. Verify that DTC P0C78 or P3061 does not set while operating the vehicle within the Conditions for Running the DTC.
      • If the DTC sets, replace the A28 hybrid/EV battery contactor assembly
      • If the DTC does not set, All OK.
    • Go to next step: If greater than the specified range 
  5. Replace the A28 Hybrid/EV Battery Contactor Assembly.
  6. Verify the DTC does not set while operating the vehicle within the Conditions for Running the DTC.
    • Go to next step: If the DTC sets 

      Go to next step: Replace the K114B Hybrid Powertrain Control Module 2.

    • Go to next step: If the DTC does not set 
  7. All OK.
scientia non olet · About LEMON Manuals