The solar sensor is installed on the upper part of the instrument panel. The solar sensor detects the amount of solar radiation and controls the "AUTO" function of the air conditioner. The out put voltage of the solar sensor changes according to the amount decreases, the voltage increases. The air conditioning amplifier reads the output voltage from the solar sensor.

Resistance of photodiode





Weak Strong



Detection Item

Trouble Area


Open or short in Solar sensor circuit. (If the check is performed in a dark place, DTC B1421/21 may be displayed.) (Passenger side)

• Harness or connector between A/C solar sensor and A/C amplifier

• A/C amplifier

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

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