LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2018 >> Terrain Denali, FWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 24 (Automatic Transmission - 6T40 (MNH MNK) Or 6T45 (MHG) - Diagnostic Information And Procedures) >> Diagnostic Information And Procedures >> DTC P171A, P171B, Or P171C: Transmission Fluid Pressure Accumulator Solenoid Valve Control Circuit >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
    NOTE:

    You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

  1. Ignition ON.
  2. Verify a test lamp illuminates on both test points of the ignition circuit fuse that provides power to the B280 Automatic Transmission Accumulator Solenoid Valve.
    • If the test lamp illuminates on 1 test point and the fuse is open 
    1. Ignition OFF.
      2. NOTE:

      There are multiple ignition circuits protected by this fuse.

    2. Disconnect all components protected by this fuse.
    3. Test for infinite resistance between the ignition circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, determine which component on the ignition circuit is causing the fuse to open, and replace the component.
      • Go to next step: If the test lamp illuminates on both test points 
  3. Ignition OFF, disconnect the harness connector at the B280 Automatic Transmission Accumulator Solenoid Valve. Ignition ON.
  4. Verify a test lamp illuminates between the ignition circuit terminal 1 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Ignition OFF, remove the test lamp.
    2. Test for less than 2 Ω in the ignition circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the X50A Fuse Block - Underhood.
    • Go to next step: If the test lamp illuminates 
  5. Connect a test lamp between the ignition circuit terminal 1 and the control circuit terminal 2.
  6. Verify the test lamp turns ON and OFF when commanding the Transmission Fluid Pressure Accumulator Solenoid Valve On and Off with a scan tool.
    • If the test lamp is always OFF 
    1. Ignition OFF, disconnect the X3 harness connector at the K20 Engine Control Module, Ignition ON.
    2. Test for less than 1 V between the control circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V.
    3. Ignition OFF.
    4. 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 K20 Engine Control Module.
    • If the test lamp is always ON 
    1. Ignition OFF, disconnect the X3 harness connector at the K20 Engine Control Module.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K20 Engine Control Module.
    • Go to next step: If the test lamp turns ON and OFF 
  7. Test or replace the B280 Automatic Transmission Accumulator Solenoid Valve. Refer to Component Testing.
scientia non olet · About LEMON Manuals