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Home >> Chevrolet >> 2015 >> Cruze LT, Automatic Trans >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 12 (Engine Controls And Fuel - 2.0L (LUZ) Diesel - DTC P0430 To DTC P2080) >> Diagnostic Information and Procedures >> DTC P125A, P125B or P2294-P2296: Fuel Pressure Regulator 2 Control Circuit >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
  1. Ignition OFF.
  2. Disconnect the harness connector at the Q18B Fuel Pressure Regulator 2.
  3. Connect a test lamp between the high control circuit terminal 2 and ground. Verify the test lamp does not illuminate.
    • If the test lamp illuminates 
    1. Disconnect the harness connector at the K20 Engine Control Module.
    2. Ignition ON, Test for less than 1 V between the high control circuit terminal 2 and ground.
      • If 1 V or greater, repair the short to voltage in the circuit.
      • If less than 1 V, replace the K20 Engine Control Module.
    • If the test lamp does not illuminate 
  4. Ignition ON.
  5. Verify a test lamp illuminates between the high control circuit terminal 2 and ground.
    • If the test lamp does not illuminate 
    1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
    2. Test for less than 2 Ω in the high control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω.
    3. Test for infinite resistance between the high control circuit and ground.
      • If less than infinite resistance, repair the short to ground in the circuit.
      • If infinite resistance, replace the K20 Engine Control Module.
    • If the test lamp illuminates 
  6. Verify a test lamp does not illuminate between the low control circuit terminal 1 and ground.
    • If the test lamp illuminates 
    1. Disconnect the harness connector at the K20 Engine Control Module.
    2. Ignition ON, Test for less than 1 V between the low control circuit terminal 1 and ground.
      • If 1 V or greater, repair the short to voltage in the circuit.
      • If less than 1 V, replace the K20 Engine Control Module.
    • If the test lamp does not illuminate 
  7. Verify a test lamp illuminates between the low control circuit terminal 1 and B+.
    • If the test lamp does not illuminate 
    1. Disconnect the harness connector at the K20 Engine Control Module.
    2. Test for less than 2 Ω in the low 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 illuminates 
  8. Ignition OFF.
  9. Observe that the test lamp flashes 2 times and remains OFF until the ECM is powered down.
    • If the test lamp does not flash 2 times and turn off 

      Test the low control circuit for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.

    1. Disconnect the harness connector at the K20 Engine Control Module.
    2. Test for infinite resistance between the low control circuit terminal 1 and ground.
      • If less than infinite resistance, repair the short to ground in the circuit.
      • If infinite resistance, replace the K20 Engine Control Module.
    • If the test lamp flashes 2 times and turns off 
  10. Replace the Q18B Fuel Pressure Regulator 2.
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