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Home >> Chevrolet >> 2006 >> Silverado 1500 HD, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1053 (Engine Controls And Fuel - 6.6L - DTC P02E7 To DTC P0699) >> DTC P0405 or P0406 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, test for less than 1 ohm of resistance between the low reference circuit terminal B 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.
  2. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal A 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.
  3. Ignition ON, and the EGR valve disconnected, observe that the EGR Position parameter on the scan tool is 0 volt.
    • If the EGR Position parameter is more than 0 volt, test the signal circuit for a short to voltage. If the circuits test normal, replace the ECM.
  4. Ignition ON and the EGR valve disconnected, connect a jumper wire between the 5-volt reference circuit terminal A and the signal circuit terminal C and observe with a scan tool that the EGR sensor parameter displays 4.98-5.02 volts.
    • If the EGR Sensor parameter is less than 4.98 volts, test the signal circuit for an open, short to ground, or high resistance. If the circuits test normal, replace the control module.
  5. If the circuits, test normal replace the EGR valve motor.
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