Did you review the Heater Core Description, the Blower Motor Description and the Air Distribution System Description and perform the necessary inspections?

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Go to Step 2

Go to Symptoms in HVAC Systems - Manual

Inspect the coolant level in the radiator and the reservoir.

Is the coolant level low?

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Go to Cooling System Leak Testing in Engine Cooling

Go to Step 3

1. Connect the scan tool.
2. Start the engine.
3. Select engine cooling temperature (ECT) in Engine Data 2.
4. Monitor the engine coolant temperature.

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

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Go to Step 4

Go to Engine Fails To Reach Normal Operating Temperature in Engine Cooling

Is the blower motor working properly in all positions?

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Go to Step 5

Go to Symptoms in HVAC Systems - Manual

Is the air distribution delivery working properly?

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Go to Step 6

Go to Symptoms in HVAC Systems - Manual

Does the air temperature change with a change in temperature control position?

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Go to Step 7

Go to Symptoms in HVAC Systems - Manual

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

Do the inlet and the outlet hoses feel hot and close in temperature?

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Go to Step 8

Go to Step 9

The problem is not present at this time. Contact the customer and gain more information about weather and drive conditions to reverify the concern.

Did you find and correct the condition?

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Go to Step 11

System OK

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

Did you find and correct the condition?

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Go to Step 11

Go to Step 10

1. Inspect the heater core for bent fins or other obstructions.
2. Repair or replace the heater core. Refer to Heater Core Replacement in HVAC.

Did you complete the repair?

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Go to Step 11

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Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 2