Circuit/System Verification
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If DTCs P0480 or P0481 are set, diagnose those DTCs first.
- Observe the engine coolant level. The engine coolant level should be within operating range. Refer to Capacities - Approximate Fluid, and Engine Coolant in the Owner's Manual.
- Ensure that the vehicle has the correct engine coolant, with correct concentration, and is not old, contaminated or contains additives. Refer to Recommended Fluids and Lubricants in the Owner's Manual.
- 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 .
- Command the cooling fans in both low and high speed.
- If the cooling fans do not operate in both speeds, refer to Cooling Fan Inoperative .
IMPORTANT:
A small delay occurs before the ECM changes the cooling fan speed.