Circuit/System Verification

WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: If DTC P0480, P0481, or P0482 is set, diagnose that DTC first.

Observe the engine coolant level. The engine coolant level should be within operating range. Refer to Cooling System Draining and Filling (Vac-N-Fill) or Cooling System Draining and Filling (Static Fill)
Ensure that the vehicle has the correct engine coolant, with correct concentration, and is not old, contaminated or contains additives. Refer to Cooling System Draining and Filling (Vac-N-Fill) or Cooling System Draining and Filling (Static Fill)
Inspect the cooling system for the following:
- Leaks
- Kinked or pinched hoses, especially at the radiator
- Loose, missing, or damaged radiator air seals or deflectors
- The radiator and A/C condenser for any air flow obstructions or bent fins-Refer to Symptoms - Engine Cooling .

NOTE: A small delay occurs before the ECM changes the cooling fan speed.

Command the cooling fans ON in each available speed with a scan tool.
- If the cooling fans are inoperative in any of the commanded states, refer to Cooling Fan Inoperative (without HP2) or Cooling Fan Inoperative (with HP2) .