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Home >> Chevrolet >> 2007 >> Chevy Express G2500, Van Cargo Extended, 6.6 2 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System & Fuel System - 6.6L (LLY) - DTC P0401 To DTC P2510 >> DTC P046C >> Circuit/System Testing

Circuit/System Testing

IMPORTANT: Perform the Circuit/System Verification before proceeding with the Circuit/System Testing.
  1. Capture the information and clear the DTCs with a scan tool.
  2. Turn OFF the ignition. Disconnect the EGR valve. Install the EN-48565  between the EGR valve and the harness connector. See Special Tools .
  3. Turn ON the ignition. Command the EGR valve to 50 percent and back to 0 percent. The EGR test harness lamp should turn ON between 10 percent and 50 percent, and turn OFF at 0 percent.
    • If the lamp does not turn ON and OFF, test both motor control circuits for an open/high resistance, short to voltage, or short to ground. If the circuits test normal, replace the control module.
    • If the lamp turns ON and OFF, replace the EGR valve.