Diagnosis Procedure

Symptom

• Insufficient heating
• No warm air comes out. (Air flow volume is normal.)

1. CHECK COOLING SYSTEM 
   1. Check engine coolant level and check leakage. Refer to System Inspection .
   2. Check reservoir tank cap. Refer to System Inspection .
   3. Check water flow sounds of the engine coolant. Refer to System Inspection .

   Is the inspection result normal?

   YES

   GO TO 2 .

   NO

   Refill engine coolant and repair or replace parts depending on the inspection results.

2. CHECK HEATER HOSE 

   Check installation of heater hose visually or by touching.

   Is the inspection result normal?

   YES

   GO TO 3 .

   NO

   Repair or replace parts depending on the inspection results.

3. CHECK HEATER CORE 
   1. Check temperature of inlet hose and outlet hose of front heater core.
   2. Check that inlet side of heater core is hot and the outlet side is slightly lower than/almost equal to the inlet side.
      CAUTION: Always perform the temperature inspection in a short period of time because the engine coolant temperature is very hot.

   Is the inspection result normal?

   YES

   GO TO 4 .

   YES

   GO TO 5 .

   NO

   Replace heater core. Refer to Removal and Installation .

4. CHECK PTC HEATER 

   Check PTC heater. Refer to Diagnosis Procedure .

   Is the inspection result normal?

   YES

   GO TO 5 .

   NO

   Replace PTC heater. Refer to Removal and Installation .

5. CHECK AIR LEAKAGE FROM EACH DUCT 

   Check duct and nozzle, etc. of front air conditioning system for air leakage.

   Is the inspection result normal?

   YES

   GO TO 6 .

   NO

   Repair or replace parts depending on the inspection results.

6. CHECK SETTING OF TEMPERATURE SETTING TRIMMER (FRONT) 
   1. Check setting value of temperature setting trimmer (front). Refer to Temperature Setting Trimmer .
   2. Check that temperature setting trimmer (front) is set to "- direction".
      NOTE: The control temperature can be set by the temperature setting trimmer (front).
   3. Set difference between the set temperature and control temperature to "0".

   Are the symptoms solved?

   YES

   Inspection End.

   NO

   Replace A/C auto amp. Refer to Removal and Installation .