DESCRIPTION
The room temperature sensor is installed in the instrument panel. It detects the cabin temperature to control the air conditioning AUTO mode. The resistance of the room temperature sensor changes in accordance with the cabin temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.
The A/C amplifier applies voltage (5 V) to the room temperature sensor and reads voltage changes as the resistance of the room temperature sensor changes. This sensor also sends appropriate signals to the A/C amplifier. The room temperature sensor is integrated with the room humidity sensor.
| DTC No. | DTC Detection condition | Trouble Area |
|---|---|---|
| B1411/11 | Open or short in room temperature sensor circuit | Room temperature sensor Harness or connector between room temperature sensor and A/C amplifier A/C amplifier |
Scheme 245
The ambient temperature sensor is installed in front of the condenser. It detects the ambient temperature to control air conditioning AUTO mode. This sensor is connected to the A/C amplifier and detects fluctuations in the ambient temperature. This data is used for controlling the cabin temperature. The sensor sends a signal to the A/C amplifier. The resistance of the ambient temperature sensor changes in accordance with the ambient temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.
The A/C amplifier applies voltage (5 V) to the ambient temperature sensor and reads voltage changes as the resistance of the ambient temperature sensor changes.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1412/12 | Open or short in ambient temperature sensor circuit | Ambient temperature sensor Harness or connector between ambient temperature sensor and A/C amplifier A/C amplifier |
Scheme 246
The evaporator temperature sensor is installed on the evaporator in the air conditioning unit to detect the cooled air temperature that has passed through the evaporator and to control the air conditioning. It sends appropriate signals to the A/C amplifier. The resistance of the evaporator temperature sensor changes in accordance with the cooled air temperature that has passed through the evaporator. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.
The A/C amplifier applies voltage (5 V) to the evaporator temperature sensor and reads voltage changes as the resistance of the evaporator temperature sensor changes. This sensor is used for frost prevention.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1413/13 | Open or short in evaporator temperature sensor circuit | Evaporator temperature sensor Air conditioning harness A/C amplifier |
Scheme 247
The smog ventilation sensor is installed on the front of the condenser to control automatic air inlet. This sensor detects CO and HC in the emission gas and transmits signals to the A/C amplifier.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1418/18 | Open or short in smog ventilation sensor circuit (HC, CO) | Smog ventilation sensor (emission gas sensor) Harness or connector between smog ventilation sensor (emission gas sensor) and A/C amplifier A/C amplifier |
Scheme 248
SYSTEM DESCRIPTION
The ECM sends the engine speed signal to the A/C amplifier via CAN communication.
The A/C amplifier reads the difference between compressor speed and engine speed. When the difference becomes too large, the A/C amplifier determines that the compressor is locked, and turns the magnetic clutch off.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1422/22 | Open or short in compressor lock sensor circuit | Air conditioning magnetic clutch circuit A/C compressor (A/C lock sensor) Compressor drive belt Harness or connector between A/C compressor and A/C amplifier A/C amplifier CAN communication system |
Scheme 249
The ECM sends the engine speed signal to the A/C amplifier via CAN communication.
The A/C amplifier reads the difference between compressor speed and engine speed. When the difference becomes too large, the A/C amplifier determines that the compressor is locked, and turns the magnetic clutch off.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1422/22 | Open or short in compressor lock sensor circuit | Air conditioning magnetic clutch circuit A/C compressor (A/C lock sensor) Compressor drive belt Harness or connector between A/C compressor and A/C amplifier A/C amplifier CAN communication system |
This DTC is output when refrigerant pressure on the high pressure side is extremely low (190 kPa (1.9 kgf/cm 2 , 28 psi) or less) or extremely high (3140 kPa (32.0 kgf/cm 2 , 455 psi) or more). The A/C pressure sensor is installed on the high pressure line. It detects refrigerant pressure to output a refrigerant pressure signal to the A/C amplifier. The A/C amplifier converts this signal to a pressure value according to the sensor characteristics to control the compressor.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1423/23 | Open or short in pressure sensor circuit Refrigerant pressure on the high pressure line is extremely low (190 kPa (1.9 kgf/cm 2 , 28 psi) or less) or extremely high (3140 kPa (32.0 kgf/cm 2 , 455 psi) or more). | A/C pressure sensor Harness or connector between A/C pressure sensor and A/C amplifier A/C amplifier Expansion valve (blocked, stuck) Condenser (blocked, deterioration of cooling capacity due to dirt) Cooler dryer (moisture in the refrigerant cycle cannot be absorbed) Cooling fan system (condenser cannot be cooled down) A/C system (leaks, blocked) |
Scheme 250
The air mix control servo motor sends pulse signals to indicate the damper position to the A/C amplifier. The A/C amplifier activates the motor (normal or reverse) based on these signals to move the air mix damper (front passenger side) to any position. As a result, the amount of air passing through the heater core after passing through the evaporator is adjusted, and the temperature of the air blowing toward the passenger side is controlled.
The A/C amplifier communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness.
HINT
Confirm that no mechanical problem is present because this DTC can be output when either a damper link or the damper is mechanically locked.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1441/41 | Air mix damper position sensor value does not change even if A/C amplifier operates air mix control servo motor | Air mix control servo motor (for front passenger side) Air conditioning harness A/C amplifier |
Scheme 251
The air inlet control servo motor sends pulse signals to indicate the damper position to the A/C amplifier. The A/C amplifier activates the motor (normal or reverse) based on these signals to move the air inlet mode selection air inlet control damper to any position, which controls the intake air settings (FRESH, FRESH/RECIRCULATION, and RECIRCULATION).
The A/C amplifier communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness.
HINT
Confirm that no mechanical problem is present because this DTC can be output when either a damper link or the damper is mechanically locked.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1442/42 | Air inlet damper position sensor value does not change even if A/C amplifier operates air inlet control servo motor | Air inlet control servo motor Air conditioning harness A/C amplifier |
Scheme 252
The air outlet control servo motor sends pulse signals to indicate the damper position to the A/C amplifier. The A/C amplifier activates the motor (normal or reverse) based on these signals to move the mode damper to any position, which controls the air outlet switching.
The A/C amplifier communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness.
HINT
Confirm that no mechanical problem is present because this DTC can be output when either a damper link or the damper is mechanically locked.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1443/43 | Air outlet damper position sensor value does not change even if A/C amplifier operates air outlet control servo motor | Air outlet control servo motor Air conditioning harness A/C amplifier |
Scheme 253
The air mix control servo motor sends pulse signals to indicate the damper position to the A/C amplifier. The A/C amplifier activates the motor (normal or reverse) based on these signals to move the air mix damper (driver side) to any position. As a result, the amount of air passing through the heater core after passing through the evaporator is adjusted, and the temperature of the air blowing toward the driver side is controlled.
The A/C amplifier communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness.
HINT
Confirm that no mechanical problem is present because this DTC can be output when either a damper link or the damper is mechanically locked.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1446/46 | Air mix damper position sensor value does not change even if A/C amplifier operates air mix control servo motor | Air mix control servo motor (for driver side) Air conditioning harness A/C amplifier |
Scheme 254
In this circuit, the A/C compressor receives a refrigerant compression demand signal from the A/C amplifier.
Based on this signal, the A/C compressor changes the amount of compressor output.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1451/51 | Open or short in A/C compressor solenoid circuit | A/C compressor (solenoid valve) Harness or connector between A/C amplifier and A/C compressor (solenoid valve) A/C amplifier |
Scheme 255
The smog ventilation sensor detects NOx in the emission gas and transmits signals to the A/C amplifier. Based on the signals, the A/C amplifier performs automatic air inlet control (FRESH, FRESH/RECIRCULATION or RECIRCULATION mode).
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1461/61 | Open or short in emission gas NOx sensor circuit | Smog ventilation sensor (emission gas NOx sensor) Harness or connector between smog ventilation sensor (emission gas NOx sensor) and A/C amplifier A/C amplifier |
Scheme 256
The A/C mass flow sensor, which is mounted on the A/C compressor, is used to detect the amount of refrigerant flow. The A/C mass flow sensor converts the amount of refrigerant flow that is detected to a voltage value to send it to the A/C amplifier. The voltage value sent from the A/C mass flow sensor changes depending on the amount of refrigerant flow. As the amount of refrigerant flow becomes larger, the voltage becomes lower. As the amount of refrigerant flow becomes smaller, the voltage becomes higher. The A/C amplifier supplies 5 V to the A/C mass flow sensor and monitors changes in the voltage value sent from the A/C mass flow sensor. The A/C amplifier then sends a signal to the ECM via CAN communication to allow the ECM to control the engine speed while the air conditioning is on.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1479/79 | Open or short in A/C mass flow sensor circuit | A/C compressor (A/C mass flow sensor) Harness or connector between A/C compressor (A/C mass flow sensor) and A/C amplifier A/C amplifier |
Scheme 257
The air conditioning harness connects the A/C amplifier and each servo. The A/C amplifier supplies power and sends operation instructions to each servo through the air conditioning harness. Each servo sends the damper position information to the A/C amplifier.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1497/97 | Communication line error or open | Air conditioning harness Air mix control servo motor (for driver side) Air mix control servo motor (for front passenger side) Air outlet control servo motor Air inlet control servo motor A/C amplifier |
Scheme 258
The solar sensor is installed on the upper side of the instrument panel. It detects sunlight to control air conditioning AUTO mode. The output voltage from the solar sensor varies in accordance with the amount of sunlight. When the amount of sunlight increases, the output voltage increases. As the sunlight decreases, the output voltage decreases. The A/C amplifier detects changes in the output voltage from the solar sensor.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| B14A3 | Short in passenger side solar sensor circuit | Solar sensor Harness or connector between solar sensor and A/C amplifier Harness or connector between solar sensor and main body ECU Main body ECU A/C amplifier |
Scheme 259
| DTC No. | DTC Detecting Condition | Trouble Area |
|---|---|---|
| U0100 | No communication with ECM | CAN communication system ECM |
| U0101 | No communication with TCM | CAN communication system TCM |
| U0131 | No communication with electric power steering ECU | CAN communication system Electric power steering ECU |
| U0142 | No communication with main body ECU | CAN communication system Main body ECU |
| U0155 | No communication with combination meter | CAN communication system Combination meter |
| DTC No. | DTC Detecting Condition | Trouble Area |
|---|---|---|
| U0100 | No communication with ECM | CAN communication system ECM |
| U0101 | No communication with TCM | CAN communication system TCM |
| U0131 | No communication with electric power steering ECU | CAN communication system Electric power steering ECU |
| U0142 | No communication with main body ECU | CAN communication system Main body ECU |
| U0155 | No communication with combination meter | CAN communication system Combination meter |
w/ Multi-display
- A/C control panel switch signals are sent to the A/C amplifier via CAN communication.
w/o Multi-display
- A/C control panel switch signals are sent to the accessory meter assembly via AVC-LAN communication. The accessory meter assembly then sends these signals to the A/C amplifier via LIN communication.
Scheme 260
Scheme 261
Scheme 262
- w/ Navigation System or w/ Audio and Visual System (w/ Multi-display with Parking Assist Monitor System)
- w/ Audio and Visual System (w/ Multi-display without Parking Assist Monitor System)
- w/ Audio and Visual System (w/o Multi-display)
w/ Multi-display
- A/C control panel switch signals are sent to the A/C amplifier via CAN communication.
w/o Multi-display
- A/C control panel switch signals are sent to the accessory meter assembly via AVC-LAN communication. The accessory meter assembly then sends these signals to the A/C amplifier via LIN communication.
The blower motor is operated by signals from the A/C amplifier. Blower motor speed signals are transmitted in accordance with changes in the duty ratio.
Scheme 263
When the A/C amplifier is turned on, a magnetic clutch ON signal is sent from the MGC terminal of the A/C amplifier. Then, the MG/CLT relay turns on to operate the magnetic clutch.
Scheme 264
When the A/C amplifier is turned on, a magnetic clutch ON signal is sent from the MGC terminal of the A/C amplifier. Then, the MG/CLT relay turns on to operate the magnetic clutch.
The main power source is supplied to the A/C amplifier when the engine switch is on (IG).
The power source is used for operating the A/C amplifier and servo motor, etc.
Scheme 265
The back-up power source circuit for the A/C amplifier is shown below. Power is supplied even when the engine switch is turned off. The power is used for diagnostic trouble code memory etc.
