1. Measure the temperature around the ambient temperature sensor and measure the resistance between the ambient temperature sensor terminal.

If the characteristics of the ambient temperature sensor are not as shown in the graph, replace the ambient temperature sensor.
Airflow Volume Control [Full Auto Air Conditioner]
Ambient Temperature Sensor Inspection [Manual Air Conditioner]Ion Sensor
Purpose/Function
Detects ion generation in the combustion chamber for detecting pre-ignition.
Detects ions which occur due to fuel combustion as current by applying bias
voltage to the spark plug, which is amplified in the ignition coil internal
circuit and input to the PCM.
...
Air Intake Actuator [Full Auto Air Conditioner]
Purpose
The air intake actuator moves the air intake door in the blower unit to switch
the air intake port.
Function
The air intake actuator drives the motor based on the signal from the climate
control unit and moves the air intake door to the FRESH or REC position.
...
Cylinder Head Gasket
Purpose, Function
The cylinder head gasket is installed between the cylinder head and cylinder
block to prevent leakage of air-fuel mixture, combustion gas, engine oil, and
engine coolant.
Construction
A four-layer type metal gasket has been adopted for the cylinder head ga ...