For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
1 | With the ignition switch in the ON position, turn the blower speed switch from OFF to each of the following settings:

1. LOW
2. MEDIUM 1
3. MEDIUM 2
4. HIGH
5. OFF

Does the blower motor speed increase at each speed level when you turn the selector switch toward HIGH?

Go to Step 2

Go to HVAC System Check

2 |

1. Inspect the engine coolant level. Refer to Coolant Concentration Testing in Engine Cooling.
2. Inspect the tension of the coolant pump drive belt. Refer to Drive Belt Replacement 1.0L or Drive Belt Replacement to to 1.3L in Engine Mechanical.
3. Inspect the radiator and the heater hoses for leaks and for kinks. Refer to Cooling System Leak Testing in Engine Cooling.
4. Inspect the radiator cap for proper operation.

Is the repair complete?

Go to Step 15

Go to Step 3

3 |

1. Inspect the thermostat for correct installation and for correct operation. Refer to Thermostat Diagnosis and Engine Coolant Thermostat Replacement to in Engine Cooling.
2. Replace the thermostat as necessary. Refer to Engine Coolant Thermostat Replacement in Engine Cooling.

Is the repair complete?

Go to Step 15

Go to Step 4

4 |

1. Set the mode control to the HEAT position.
2. Set the blower speed to the HIGH position.
3. Set the temperature control to the hottest position.
4. Turn the ignition switch to the ON position.
5. Inspect for airflow from the heater outlets.

Is there high airflow from the heater outlets?

Go to Step 7

Go to Step 5

5 | Inspect the mode control cable and the linkages. Refer to Mode Control Cable Adjustment . Is the repair complete? | Go to Step 15 | Go to Step 6
6 |

1. Inspect the system for obstructions between the blower and the system outlets. Refer to Heater Case Replacement .
2. Inspect the system for obstructions at the blower inlet and at the plenum.
3. Remove the obstructions, as necessary.

Is the repair complete?

Go to Step 15

--

7 |

1. Turn the blower speed switch to the highest position.
2. Set the temperature control to the hottest position.

Caution: The cooling system is pressurized when hot.

3. With the engine cold, remove the radiator cap.
4. Start the engine, and idle until the coolant flow is visible inside the radiator.
5. Install the radiator cap.
6. Drive the vehicle at 48 km/h (30 mph) for at least 20 minutes.
7. Using a thermometer, record the ambient air temperature.
8. Using a thermometer, record the discharge air temperature at the heater outlet.
9. Using the following table, compare the heater outlet temperature with the ambient air temperature:

• | 54°C (130°F) at -18°C (0°F)

• | 59°C (139°F) at -4°C (25°F)

• | 64°C (147°F) at 10°C (50°F)

• | 68°C (155°F) at 24°C (75°F)

Is the heater outlet temperature within the specified values?

Go to Step 8

Go to Step 9

8 |

1. Inspect the vehicle for cold air leaks at the following locations:

• | The instrument panel

• | The heater case

• | The front vents

2. Inspect for obstructions under the seats.
3. Remove the obstructions, as necessary.

Is the repair complete?

Go to Step 15

--

9 |

1. Turn the ignition switch to the LOCK position.
2. Test the temperature door operation by moving the temperature control quickly from the coldest position to the hottest position and back to the coldest position.

Do you hear the temperature door close at each end?

Go to Step 11

Go to Step 10

10 | Inspect the temperature control cable and the linkages. Refer to Temperature Control Cable Adjustment . Is the repair complete? | Go to Step 15 | --
11 |

1. Set the temperature control to the hottest position.
2. Start the engine.
3. Feel the inlet and the outlet heater hoses.

Does the inlet heater hose feel hot, and does the outlet heater hose feel warm?

Go to Step 13

Go to Step 12

12 |

1. Inspect for the correct heater hose location. Refer to Heater Hoses Replacement .
2. Repair the heater hoses, as necessary.

Is the repair complete?

Go to Step 15

--

13 |

1. Flush the heater core. Refer to Flushing in Engine Cooling.
2. Drain and fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
3. Set the temperature control to the hottest position.
4. Start the engine.
5. Feel the inlet and the outlet heater hoses.

Does the inlet heater hose feel hot, and does the outlet heater hose feel warm?

Go to Step 15

Go to Step 14

14 | Replace the heater core. Refer to Heater Core Replacement . Is the repair complete? | Go to Step 15 | --
15 | Perform the function test. Refer to Function Test . Is the repair complete? | System OK | --