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Home >> Chevrolet >> 2018 >> Equinox L >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 21 (Automatic Transmission - 9T45 (M3U) Or 9T50 (M3D M3H) - Diagnostic Information And Procedures) >> Diagnostic Information And Procedures >> DTC P171A, P171B, P171C: Transmission Accumulator Solenoid Valve Control Circuit >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
  1. Ignition/Vehicle - Off
  2. Disconnect the electrical connector: B280 Automatic Transmission Accumulator Solenoid Valve
  3. Connect a test lamp between the test points: Control circuit terminal 1 & Ground
  4. Ignition - On/Vehicle - In Service Mode
  5. Perform the scan tool control function: High Side Driver 1 - On and Off

    Verify the test lamp turns On and Off.

    • If the test lamp is always Off 
    1. Ignition/Vehicle - Off & Remove - Test lamp
    2. Disconnect the electrical connector: K71 Transmission Control Module
    3. Test for infinite resistance between the test points: Control circuit terminal 1 @ Component harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance
    4. Test for less than 2 Ω between the test points: Control circuit terminal 1 @ Component harness & Terminal 33 @ Control module harness
      • If 2 Ω or greater - Repair the open/high resistance in the circuit.
      • If less than 2 Ω - Replace the component: K71 Transmission Control Module
    • If the test lamp is always On 
    1. Ignition/Vehicle - Off & Remove - Test lamp
    2. Disconnect the electrical connector: K71 Transmission Control Module
    3. Ignition - On/Vehicle - In Service Mode
    4. Test for less than 1 V between the test points: Control circuit terminal 1 @ Component harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • If less than 1 V - Replace the component: K71 Transmission Control Module
    • Go to next step: If the test lamp turns On and Off 
  6. Remove - Test Lamp
  7. Ignition/Vehicle - Off
  8. Disconnect the electrical connector: K71 Transmission Control Module
  9. Test for less than 2 Ω between the test points: Control circuit terminal 2 @ Component harness & Terminal 24 @ Control module harness
    • If 2 Ω or greater 

      Repair the open/high resistance in the circuit.

    • Go to next step: If less than 2 Ω 
  10. Test for infinite resistance between the test points: Control circuit terminal 2 & Ground
    • If less than infinite resistance 

      Repair the short to ground on the circuit.

    • Go to next step: If infinite resistance 
  11. Ignition - On/Vehicle - In Service Mode
  12. Test for less than 1 V between the test points: Control circuit terminal 2 & Ground
    • If 1 V or greater 

      Repair the short to voltage on the circuit.

    • Go to next step: If less than 1 V 
  13. Ignition/Vehicle - Off
  14. NOTE:

    The component's temperature should be 19 to 21°C (66 to 70°F) while testing.

  15. Test for 17 to 19 Ω between the test points: Control terminal 1 & Control terminal 2
    • If not between 17 and 19 Ω 

      Replace the component: B280 Automatic Transmission Accumulator Solenoid Valve

    • Go to next step: If between 17 and 19 Ω 
  16. Test for infinite resistance between the test points: Each terminal of the component & The component's housing
    • If less than infinite resistance 

      Replace the component: B280 Automatic Transmission Accumulator Solenoid Valve

    • Go to next step: If infinite resistance 
  17. Replace the component: K71 Transmission Control Module