1

1. Turn the engine to the OFF position.
2. Wait until the engine temperature is cool.
3. Inspect the coolant level in the following components:

•	The radiator

•	The reservoir

Is the coolant level low?

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Go to Step 5

Go to Step 2

1. Connect the scan tool .
2. Start the engine.
3. Monitor the temperature of the engine coolant.

Does the coolant temperature increase steadily to a normal operating temperature?

--

Go to Step 3

Go to Step 6

Feel the inlet hose and the outlet hose of the heater core.

Do both the inlet hose and the outlet hose feel hot?

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Go to Step 4

Go to Step 7

Inspect the heater core for bent fins or other obstructions. Repair the heater core as necessary.

Is the repair complete?

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System OK

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1. Inspect the cooling system for leakage. Repair any leaks as necessary.
2. Fill the coolant system using air.
3. Bleed the air from the coolant system. Refer to Engine Cooling.
4. Fill the coolant system using coolant.

Is the coolant system full?

--

System OK

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The thermostat is faulty. Replace the faulty thermostat. Refer to Engine Coolant Thermostat Replacement .

Is the repair complete?

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System OK

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1. Inspect the hoses for kinks or other obstructions.
2. Flush or replace the obstructed heater core.

Is the repair complete?

--

System OK

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