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Home >> Chevrolet >> 2016 >> Spark LS, Automatic CVT Trans >> Repair and Diagnosis (Single Page) >> Transmission >> Automatic Trans >> Automatic Transmission - JATCO CVT >> Diagnostic Information and Procedures >> DTC P0863: Transmission Control Module (TCM) Communication Circuit - (ROM Assembly) >> Circuit/System Testing
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Circuit/System Testing

  1. Ignition OFF.
  2. Disconnect the Q8 Control Solenoid Valve Assembly connector.
  3. Test for greater than 1.0 M Ω between each of the following circuits and ground.
    • Transmission Manual/Automatic Data Output circuit, terminal 17
    • Transmission Manual/Automatic Data Clock circuit, terminal 16
    • Transmission Manual/Automatic Select Direction Signal circuit, terminal 15
    • If 1.0 M Ω or less 

      Repair the short to ground in the affected circuit.

    • If greater than 1.0 M Ω 
  4. Test for infinite resistance between each of the following circuits and all other terminals of the Q8 Control Solenoid Valve Assembly connector.
    • Transmission Manual/Automatic Data Output circuit, terminal 17
    • Transmission Manual/Automatic Data Clock circuit, terminal 16
    • Transmission Manual/Automatic Select Direction Signal circuit, terminal 15
    • If less than infinite resistance 

      Repair the short together in the affected circuits.

    • If infinite resistance 
  5. Disconnect the K71 Transmission Control Module X2 harness connector.
  6. Test for less than 5 Ω resistance in the following circuits end to end.
    • Transmission Manual/Automatic Data Output circuit, Q8 Control Solenoid Valve Assembly connector terminal 17 to K71 Transmission Control Module harness connector X2 terminal 21
    • Transmission Manual/Automatic Data Clock circuit, Q8 Control Solenoid Valve Assembly connector terminal 16 to K71 Transmission Control Module harness connector X2 terminal 13
    • Transmission Manual/Automatic Select Direction Signal circuit, Q8 Control Solenoid Valve Assembly connector terminal 15 to K71 Transmission Control Module harness connector X2 terminal 22
    • If 5 Ω or greater 

      Repair the open/high resistance in the affected circuit.

    • If less than 5 Ω 
  7. Connect the Q8 Control Solenoid Valve Assembly connector and the K71 Transmission Control Module X2 harness connector.
  8. Ignition ON.
  9. Using a scan tool, erase the CVT calibration data in the TCM.
  10. Using a scan tool, run the CVT calibration process.
  11. Clear DTC P0863.
  12. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data. The DTC should not set.
    • If the DTC sets 

      Replace the component:Q8 Control Solenoid Valve Assembly

    • If the DTC does not set 
  13. All OK.
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