Insufficient Heating

INSUFFICIENT HEATING


Component Function Check

SYMPTOM: Insufficient heating

INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - TEMPERATURE INCREASE
1. Press the AUTO switch.
2. Turn the temperature control dial (driver) clockwise until 32�C (90�F) is displayed.
3. Check for hot air at discharge air outlets.
Can this symptom be duplicated?
YES - GO TO 2.
NO - Perform complete system operational check. Refer to Operational Check (Front).
2.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 3.
3.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis. Refer to A/C Auto AMP. Self-Diagnosis.
Is the inspection result normal?
YES - GO TO 4.
NO - Refer to A/C System Self-Diagnosis Code Chart.
4.CHECK ENGINE COOLING SYSTEM
1. Check for proper engine coolant level. Refer to Inspection.
2. Check hoses for leaks or kinks.
3. Check radiator cap. Refer to Inspection.
4. Check for air in cooling system.
>> GO TO 5.
5.CHECK AIR MIX DOOR OPERATION
Check the operation of the air mix door.
Is the inspection result normal?
YES - GO TO 6.
NO - Check the air mix door motor circuit. Refer to Air Mix Door Motor.
6.CHECK AIR DUCTS
Check for disconnected or leaking air ducts.
Is the inspection result normal?
YES - GO TO 7.
NO - Repair all disconnected or leaking air ducts.
7.CHECK HEATER HOSE TEMPERATURES
1. Start engine and warm it up to normal operating temperature.
2. Touch both the inlet and outlet heater hoses.
Is the inspection result normal?
YES - Hot inlet hose and a warm outlet hose: GO TO 8.
NO - � Inlet hose cold: GO TO 11.
- Both hoses warm: GO TO 9.
8.CHECK ENGINE COOLANT SYSTEM
Check engine control temperature sensor. Refer to P0117.
Is the inspection result normal?
YES - System OK.
NO - Repair or replace as necessary. Retest.
9.CHECK HEATER HOSES
Check heater hoses for proper installation.
Is the inspection result normal?
YES - System OK.
NO - 1. Back flush heater core.
2. Drain the water from the system.
3. Refill system with new engine coolant. Refer to Changing Engine Coolant.
4. GO TO 10 to retest.
10.CHECK HEATER HOSE TEMPERATURES
1. Start engine and warm it up to normal operating temperature.
2. Touch both the inlet and outlet heater hoses.
Is the inspection result normal?
YES - System OK.
NO - Replace heater core. Refer to Removal and Installation.
11.CHECK WATER VALVE
Check the operation of the water valve. Refer to Water Valve Circuit.
Is the inspection result normal?
YES - System OK.
NO - Replace water valve.