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Home >> Buick >> 2015 >> Regal GS, AWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 15 (Engine Controls And Fuel - 2.4L - DTC P0114 To DTC P0604) >> Diagnostic Information and Procedures >> DTC P0443, P0458, or P0459: Evaporative Emission (EVAP) Purge Solenoid Valve >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
  1. Ignition OFF, disconnect the harness connector at the Q12 Evaporative Emission Purge Solenoid Valve. Ignition ON,
  2. Verify that a test lamp illuminates between the ignition voltage circuit terminal A or 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 2Ω in the ignition circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, verify the fuse is not open and there is voltage at the fuse
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Ignition OFF, remove the test lamp.
    2. 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, test all components connected to the ignition voltage circuit for a short and replace as necessary.
    • If the test lamp illuminates 
  3. Verify that a test lamp does not illuminate between the ignition circuit terminal A or 1 and the control circuit terminal B or 2.
    • If the test lamp illuminates 
    1. Ignition OFF, remove the test lamp, disconnect the 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.
    • If the test lamp does not illuminate 
  4. Remove the test lamp.
  5. Verify the scan tool EVAP Purge Solenoid Valve Control Circuit High Voltage Test Status parameter is OK when commanding the EVAP Purge Solenoid Valve to 50% with a scan tool.
    • If OK is not displayed 
    1. Ignition OFF, disconnect the harness connector at the K20 engine Control Module, Ignition ON.
    2. Test for less than 1V between the control circuit and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V, replace the K20 engine Control Module.
    • If OK is displayed 
  6. Install a 3A fused jumper wire between the control circuit terminal B or 2 and the ignition circuit terminal A or 1.
  7. Verify the scan tool EVAP Purge Solenoid Valve Control Circuit High Voltage Test Status parameter is Malfunction when commanding the EVAP Purge Solenoid Valve to 50% with a scan tool.
    • If Malfunction is not displayed 
    1. Ignition OFF, remove the jumper wire, disconnect the harness connector at the K20 engine Control Module.
    2. Test for less than 2Ω in the control circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω replace the K20 engine Control Module.
    • If Malfunction is displayed 
  8. Test or replace the Q12 Evaporative Emission Purge Solenoid Valve.
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