Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Chevrolet >> 2009 >> Chevy Express G2500, Van Cargo Extended, 6.6 6 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System & Fuel System - 6.6L LMM - DTC P1224 To DTC P2463 >> DTC P2454 or P2455 >> Circuit/System Testing

Circuit/System Testing

    IMPORTANT: Perform the Repair Verification after completing the Circuit/System Testing.
  1. Visually and physically inspect the DPF pressure differential lines for the following conditions:
    • A loose fit
    • Any cracking
    • An internal restriction
    • Incorrect routing-Ensure the smaller diameter pressure line is connected to the front of the DPF, and to the smaller port of the differential pressure sensor.
    • If a condition is found, repair or replace the differential pressure lines as necessary.
  2. Ignition OFF, disconnect the harness connector at the exhaust differential pressure sensor.
  3. Ignition OFF and scan tool disconnected for 90 seconds, measure for less than 5 ohms between the low reference circuit terminal 1 and ground.
    • If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  4. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground.
    • If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
    • If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  5. Verify the scan tool Particulate Filter Pressure Variance parameter is greater than 98 kPa.
    • If less than the specified range, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the ECM.
  6. Install a 3A fused jumper wire between the signal circuit terminal 2 and the low reference circuit terminal 1. Verify the scan tool Particulate Filter Pressure Variance parameter is less than 13 kPa.
    • If greater than the specified range, test the signal circuit terminal 2 for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
  7. If all circuits and the exhaust differential pressure sensor lines test normal, test the exhaust differential pressure sensor.
scientia non olet · About Mike's Workshop Manuals