LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2020 >> Express 2500 LS, 6.0L Eng VIN G >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 24 (Engine Controls And Fuel - 2.8L (LWN) Diesel - Diagnostic Information And Procedures (1 Of 3)) >> Diagnostic Information and Procedures >> DTC P0403, P1402, P1407, P140F, or P1424 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
  1. Verify a condition does not exist with the component : Q14 Exhaust Gas Recirculation Valve
    • Corrosion - Electrical Connector
    • Visible Damage
    • Stuck/Restricted
    • If a condition exists 

      Repair as necessary

    • Go to next step : If no conditions exist 
  2. Ignition/Vehicle & All vehicle systems - Off
  3. Disconnect the electrical connector : Q14 Exhaust Gas Recirculation Valve
  4. Ignition - On / Vehicle - In Service Mode
  5. Test for 0.1 to 0.5 V between the test points : Control circuit terminal 5 & Ground
    • If greater than 0.5 V 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector : K20 Engine Control Module
    3. Ignition - On / Vehicle - In Service Mode
    4. Test for less than 1 V between the test points : Control circuit terminal 5 @ Component harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • If less than 1 V - Replace the component : K20 Engine Control Module
    • If less than 0.1 V 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector : K20 Engine Control Module
    3. Test for less than 2 ohms between the test points : Control circuit terminal 5 @ Component harness & Terminal 70 X2 @ Control module harness
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • Go to next step : If less than 2 ohms
    4. Test for infinite resistance between the test points : Control circuit terminal 5 @ Component harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance - Replace the component : K20 Engine Control Module
    • Go to next step : If between 0.1 and 0.5 V 
  6. Test for 1 to 3 V between the test points : Control circuit terminal 1 @ Component harness & Ground
    • If greater than 3 V 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector : K20 Engine 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 : K20 Engine Control Module
    • If less than 1 V 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector : K20 Engine Control Module
    3. Test for less than 2 ohms between the test points : Control circuit terminal 1 @ Component harness & Terminal 71 X2 @ Control module harness
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • Go to next step : If less than 2 ohms
    4. 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 - Replace the component : K20 Engine Control Module
    • Go to next step : If between 1 and 3 V 
  7. Replace the component : Q14 Exhaust Gas Recirculation Valve
scientia non olet · About LEMON Manuals