LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2006 >> Sierra 1500 HD, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1643 (Engine Control System & Fuel System - 4.8L, 5.3L, 6.0L, 6.2L - DTC P0010 To DTC P0232/DTC P025A) >> DTC P0128 (Without L96) >> Circuit/System Verification

Circuit/System Verification

WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, and 2010 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, inspect the cooling system surge tank for the proper coolant level. Refer to Cooling System Leak Testing and Cooling System Draining and Filling (Vac-N-Fill) or Cooling System Draining and Filling (Static Fill) .
  2. Ignition OFF for 8 h or greater.
  3. Ignition ON, observe the scan tool IAT Sensor and ECT Sensor parameters. The ECT, IAT, and ambient temperatures should be within 6°C (11°F) of each other.
  4. Use the scan tool to verify the proper operation of the engine cooling system fans.
  5. NOTE: A critical analysis of the operation of the thermostat is necessary to properly diagnose these DTC.
  6. Verify the proper heat range and the operation of the thermostat. Refer to Thermostat Diagnosis .
  7. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.