LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2020 >> Malibu LS >> Repair and Diagnosis >> External Pages >> Different car >> Section 49 (Engine Controls And Fuel - 1.8L (LKN) - DTC P0010-DTC P0459) >> Diagnostic Information and Procedures >> DTC P0403, P0489, or P0490 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.
  1. Vehicle OFF, and all vehicle systems OFF, disconnect the harness connector at the Q14 Exhaust Gas Recirculation Valve.
  2. Test for less than 10 Ω between the motor ground circuit terminal 2 and ground.
    • If 10 Ω or greater 
    1. Vehicle OFF.
    2. Test for less than 2 Ω in the motor ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
    • Go to next step: If less than 10 Ω 
  3. Ignition ON/Vehicle in Service Mode.
  4. Verify the fuse is not open:F84UA Fuse
    • If the fuse is open 
    1. Vehicle OFF.
      2. NOTE:

      A short circuit in any component supplied by the fuse may cause the fuse to open and set a DTC when the component is activated.

    2. Disconnect all components on the fused circuit.
    3. Test for infinite resistance between the motor ignition circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, test all components supplied by the fuse and replace as necessary.
    • Go to next step: If the fuse is not open 
  5. Test for greater than 1 V between the test points:Ignition circuit terminal 1 & Ground
    • If less than 1 V 
    1. Vehicle OFF.
    2. Test for less than 2 Ω in the motor ignition circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
    • Go to next step: If greater than 1 V 
  6. Vehicle OFF, and all vehicle systems OFF. It may take up to 2 min for all vehicle systems to power down.
  7. Test for less than 10 Ω between the low reference circuit terminal 5 and ground.
    • If 10 Ω or greater 
    1. Vehicle OFF, disconnect the harness connector at the K20 Engine Control Module.
    2. Test for less than 2 Ω in the low reference 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.
    • Go to next step: If less than 10 Ω 
  8. Ignition ON/Vehicle in Service Mode.
  9. Test for greater than 1 V between the test points:Signal circuit terminal 3 & Ground
    • If less than 1 V 
    1. Vehicle OFF.
    2. Disconnect the harness connector at the K20 Engine Control Module.
    3. Test for less than 2 Ω in the input signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • Go to next step: If less than 2 Ω
    4. Test for infinite resistance between the input signal 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 greater than 1 V 
  10. Vehicle OFF, disconnect the harness connector at the K20 Engine Control Module, Ignition ON/Vehicle in Service Mode.
  11. Test for less than 1 V between the input signal circuit and ground.
    • If 1 V or greater 

      Repair the short to voltage on the circuit.

    • Go to next step: If less than 1 V 
  12. Vehicle OFF, connect the harness connector at the K20 Engine Control Module, Ignition ON/Vehicle in Service Mode.
  13. Test for greater than 1 V between the test points:Signal circuit terminal 4 & Ground
    • If less than 1 V 
    1. Vehicle OFF.
    2. Disconnect the harness connector at the K20 Engine Control Module.
    3. Test for less than 2 Ω in the output signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • Go to next step: If less than 2 Ω
    4. Test for infinite resistance between the output signal 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 greater than 1 V 
  14. Vehicle OFF, disconnect the harness connector at the K20 Engine Control Module, Ignition ON/Vehicle in Service Mode.
  15. Test for less than 1 V between the output signal circuit and ground.
    • If 1 V or greater,  repair the short to voltage on the circuit.
    • Go to next step: If less than 1 V 
  16. Test or replace the Q14 Exhaust Gas Recirculation Valve.
scientia non olet · About LEMON Manuals