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Home >> Chevrolet >> 2020 >> Express 2500 LS, 6.0L Eng VIN G >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 12 (Engine Controls And Fuel - 2.8L (LWN) Diesel - Diagnostic Information And Procedures (3 Of 3)) >> Diagnostic Information and Procedures >> DTC P2452-P2456 >> Circuit/System Testing

Circuit/System Testing

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  1. Verify the following conditions do not exist with the DPF system :
    • Any damaged exhaust system components
    • Loose or improperly installed exhaust system components.
    • Restrictions in the exhaust differential pressure sensor ports.
    • Damaged, bent, restricted, or kinked exhaust differential pressure lines.
    • If a condition is found 

      Repair as necessary

    • Go to next step : If no condition is found 
  2. Ignition OFF, disconnect the harness connector at the B154 Diesel Particulate Filter Exhaust Differential Pressure Sensor.
  3. Test for less than 10 Ω between the low reference circuit terminal 2 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF, disconnect the X3 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 
  4. Ignition ON, test for 4.8 - 5.2 V between the 5 V reference circuit terminal 3 and ground.
    • If less than 4.8 V 
    1. Ignition OFF, disconnect the X3 harness connector at the K20 Engine Control Module.
    2. Test for infinite resistance between the 5 V reference circuit and ground.
      • If less than infinite resistance, repair the short to ground in the circuit.
      • Go to next step : If infinite resistance
    3. Test for less than 2 Ω in the 5 V 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.
    • If greater than 5.2 V 
    1. Ignition OFF, disconnect the X3 harness connector at the K20 Engine Control Module.
    2. Test for less than 1 V in the 5 V reference circuit end to end.
      • If 1 V or greater, repair the short to voltage in the circuit.
      • If less than 1 V, replace the K20 Engine Control Module.
    • Go to next step : If between 4.8 - 5.2 V 
  5. Verify the scan tool Diesel Particulate Filter Differential Pressure Sensor parameter is greater than 4.8 V.
    • If 4.8 V or less 
    1. Ignition OFF, disconnect the X3 harness connector at the K20 Engine Control Module.
    2. Test for infinite resistance between the 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 4.8 V 
  6. Install a 3 A fused jumper wire between the signal circuit terminal 1 and ground. Verify the scan tool Diesel Particulate Filter differential pressure sensor parameter is less than 1 V.
    • If greater than 1 V 
    1. Ignition OFF, disconnect the X3 harness connector at the K20 Engine Control Module.
    2. Test for less than 1 V in the signal circuit end to end.
      • If 1 V or greater, repair the short to voltage in the circuit.
      • Go to next step : If less than 1 V
    3. Test for less than 2 Ω in the signal 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 1 V 

      Go to next step : Replace the B154 Diesel Particulate Filter Exhaust Differential Pressure Sensor.