Step
| Action
| Yes
| No
|
1
| Were
you sent here from Too Cold in Vehicle?
| Go to
Step 2
| Go to
Too Cold in Vehicle
in HVAC Systems - Manual or
Too Cold in Vehicle
in HVAC Systems - Automatic
|
2
|
- Start the engine.
- Allow the engine to idle.
Does the engine reach a normal operating temperature?
| Go to
Step 3
| Go to
Step 9
|
3
|
- Allow to idle.
- Select the FLOOR mode.
- Select the minimum blower speed.
- Select the maximum temperature setting.
- Feel the temperature of the inlet and outlet hoses at the heater
core.
Does the inlet hose feel warmer than the outlet hose?
| Go to
Step 7
| Go to
Step 4
|
4
|
- Install a thermometer into the I/P center air outlet.
- Secure a thermometer to the heater core outlet hose.
- Select the PANEL mode.
- Select the maximum blower speed.
- Select the maximum temperature setting.
- Record the temperature at the following locations:
• | The I/P center air outlet |
• | The heater core outlet hose |
- Compare the recorded temperatures.
Are the temperatures similar?
| Go to
Step
5
| Go to
Step
6
|
5
|
- Inspect and repair the following areas of the vehicle for cold
air leaks:
- Perform the necessary repairs.
Are the repairs complete?
| Go to
Step 10
| --
|
6
|
- Start the engine and allow to idle.
- Depress the mode control button until the LOWER position is displayed.
- Select the lowest blower speed position.
- Turn the temperature control knob to the maximum hot position.
- Check the temperature of the heater inlet and outlet hoses by
feel.
(The air temperature around the hoses must be
at least 24°C (85°F).
Does the heater inlet hose feel warm and the heater outlet hose feel
cold?
| Go to
Step 10
| --
|
7
|
- Turn OFF the engine.
- Backflush the heater core. Refer to
Flushing
in
Engine Cooling.
- Start the engine.
- Select the FLOOR mode.
- Select the minimum blower speed.
- Select the maximum temperature setting.
- Feel the temperature of the inlet and outlet hoses at the heater
core.
Does the inlet hose feel warmer than the outlet hose?
| Go to
Step 8
| Go to
Step 10
|
8
| Replace the heater core. Refer to
Heater Core Replacement
.
Is the repair complete?
| Go to
Step 10
| --
|
9
| Repair the low engine temperature concern. Refer to
Engine Fails To Reach Normal Operating Temperature
in Engine Cooling.
Is the repair complete?
| Go to
Step 10
| --
|
10
| Operate the system in order to verify the repair.
Does the system operate correctly?
| System OK
| Go to
Step 2
|