by ptommo59 on Sat, 22 Jul 2023 11:59 +0000
21 Solar Sensor Circuit
41 Mixing flap control servo motor circuit (passenger side)
42 Air Inlet Damper Control Servo Motor Circuit
43 Air Outlet Damper Control Servo Motor Circuit
21 - An open in cooler thermistor (solar sensor) circuit.
The cooler thermistor (solar sensor), which is installed on the upper side of the instrument panel, detects sunlight and controls the air conditioning in AUTO mode. The output current from the cooler thermistor (solar sensor) varies according to the amount of sunlight. When the amount of sunlight increases, the output current increases. As the amount of sunlight decreases, the output current decreases. The air conditioning amplifier assembly detects the output current from the cooler thermistor (solar sensor). Code can be output in normal operation if test is done in dark place.
41 - The air mix control damper position does not change when the air conditioning amplifier assembly operates the air mix damper servo sub-assembly.
The air mix damper servo sub-assembly sends pulse signals to inform the air conditioning amplifier assembly of the air mix control damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on the signals to move the air mix control damper to any position. As a result, the air mix control damper varies the mixture of hot air from the heater core and cold air from the evaporator so that the temperature of the air blowing toward the driver and front passenger side is as requested.
This DTC is also output if the damper and damper link are malfunctioning or unable to move properly. When this DTC is output, confirm that the mechanical parts of the damper and damper link are not defective or damaged.
42 - The air inlet control damper position does not change when the air conditioning amplifier assembly operates the recirculation damper servo sub-assembly.
The recirculation damper servo sub-assembly sends pulse signals to inform the air conditioning amplifier of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on the signals to move the air inlet control damper to any position, which controls the intake air settings. This DTC is also output if the air inlet control damper and damper link are malfunctioning or unable to move properly. When this DTC is output, confirm that the mechanical parts of the damper and damper link are not defective or damaged.
43 - The mode damper position does not change when the air conditioning amplifier assembly operates the mode damper servo sub-assembly.
The mode damper servo sub-assembly sends pulse signals to inform the air conditioning amplifier assembly of the mode damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on the signals to move the mode damper to any position, which controls the mode changes. This DTC is also output if the mode damper and damper link are malfunctioning or unable to move properly. When this DTC is output, confirm that the mechanical parts of the mode damper and damper link are not defective or damaged.
From Manual When DTC 41, 42 and 43 are output at same time, there would be malfunctioning on power source circuit"" It indicates that the ECU-B No.2 Fuse (7.5A Fuse 22 in Engine Bay Fuse Box) could be blown or wiring to aircon control circuit from fuse is faulty. If not either of these could be a fault in the air con amplifier.