DESCRIPTION
This DTC is stored if the amount of refrigerant in the air conditioning system is insufficient.
The air conditioning amplifier assembly receives the ambient temperature signal, refrigerant pressure signal, etc. from various sensors.
Based on these signals, the air conditioning amplifier assembly detects the amount of refrigerant.
The A/C switch indicator is turned off and the air conditioning system is stopped if the amount of refrigerant is insufficient.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory |
|---|---|---|---|---|
| B14B8 | Refrigerant Shortage | When following condition is detected in refrigerant shortage check in normal operation: Amount of refrigerant is insufficient | Refrigerant pipe line Cooler expansion valve Air conditioning amplifier assembly | Memorized (15 min. or more)*1 |
- *1: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory |
|---|---|---|---|---|
| U0100 | Lost Communication with ECM | No communication with ECM | CAN communication system ECM | Memorized |
| U0131 | Lost Communication with Electric Power Steering ECU | No communication with electric power steering ECU assembly | CAN communication system Electric power steering ECU assembly | Memorized |
| U0142 | Lost Communication with Main Body ECU | No communication with main body ECU (multiplex network body ECU) | CAN communication system Main body ECU (multiplex network body ECU) | Memorized |
| U0155 | Lost Communication with Combination Meter | No communication with combination meter assembly | CAN communication system Combination meter assembly | Memorized |
The air conditioning harness assembly connects the air conditioning amplifier assembly and the servo motors. The air conditioning amplifier assembly supplies power and sends operation instructions to each servo motor through the air conditioning harness assembly. Each servo motor sends damper position information to the air conditioning amplifier assembly.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory |
|---|---|---|---|---|
| B1497/97 | BUS IC Communication Malfunction | Error or open in communication line | Air conditioning harness assembly Air mix damper servo sub-assembly Mode damper servo sub-assembly Recirculation damper servo sub-assembly Air conditioning amplifier assembly | Memorized (10 sec. or more)*1 |
- *1: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.
Scheme 100
1, for 2ZR-FE
In this circuit, the compressor assembly with pulley (compressor solenoid) receives a refrigerant compression demand signal from the air conditioning amplifier assembly.
Based on this signal, the compressor assembly with pulley (compressor solenoid) changes the amount of compressor output.
2, for 2ZR-FAE
In this circuit, the cooler compressor assembly (compressor solenoid) receives a refrigerant compression demand signal from the air conditioning amplifier assembly.
Based on this signal, the cooler compressor assembly (compressor solenoid) changes the amount of compressor output.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory |
|---|---|---|---|---|
| B1451/51 | Compressor Solenoid Circuit | Open or short in compressor solenoid circuit | Compressor assembly with pulley (compressor solenoid)*1 Cooler compressor assembly (compressor solenoid)*2 Harness or connector between air conditioning amplifier assembly and compressor assembly with pulley (compressor solenoid)*1 Harness or connector between air conditioning amplifier assembly and cooler compressor assembly (compressor solenoid)*2 Air conditioning amplifier assembly |
- *1: for 2ZR-FE
- *2: for 2ZR-FAE
Scheme 101
Scheme 102
- CONFIRM MODEL Choose the model to be inspected. Result Result Proceed to for 2ZR-FE A for 2ZR-FAE B Result: 2 B See step 5 Result: 1 A See step 2
- INSPECT COMPRESSOR ASSEMBLY WITH PULLEY (COMPRESSOR SOLENOID) Disconnect the B8 compressor assembly with pulley (compressor solenoid) connector. Measure the resistance according to the value(s) in the table below. *a Component without harness connected (Compressor Assembly with Pulley (Compressor Solenoid)) Standard Resistance Tester Connection Condition Specified Condition 1 (SOL-) - 2 (SOL+) 20°C (68°F) 10.1 to 11.1 ohms Result Proceed to OK NG Result: 2 NG REPLACE COMPRESSOR ASSEMBLY WITH PULLEY (COMPRESSOR SOLENOID). Refer to «REMOVAL [08/2013 - ]»(/toyota/corolla/xi-2012-2016/remont/automatic-hvac-system/#air-conditioning-system-service-information) Result: 1 OK See step 3
- CHECK HARNESS AND CONNECTOR (COMPRESSOR ASSEMBLY WITH PULLEY (COMPRESSOR SOLENOID) - BODY GROUND) Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition B8-1 (SOL-) - Body ground Always Below 1 ohms Result Proceed to OK NG Result: 2 NG REPAIR OR REPLACE HARNESS OR CONNECTOR Result: 1 OK See step 4
- CHECK HARNESS AND CONNECTOR (COMPRESSOR ASSEMBLY WITH PULLEY (COMPRESSOR SOLENOID) - AIR CONDITIONING AMPLIFIER ASSEMBLY) Disconnect the E37 air conditioning amplifier assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E37-2 (SOL+) - B8-2 (SOL+) Always Below 1 ohms E37-2 (SOL+) - Body ground Always 10 kohms or higher Result Result Proceed to NG A OK (When troubleshooting according to the Problem Symptoms Table) B OK (When troubleshooting according to the DTC) C Result: 1 A REPAIR OR REPLACE HARNESS OR CONNECTOR Result: 2 B PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE [08/2013 - ]»(ref-635442-S14519101662014070300000) Result: 3 C REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL [08/2013 - ]»(/toyota/corolla/xi-2012-2016/remont/automatic-hvac-system/#air-conditioning-system-service-information)
- INSPECT COOLER COMPRESSOR ASSEMBLY (COMPRESSOR SOLENOID) Disconnect the B8 cooler compressor assembly (compressor solenoid) connector. Measure the resistance according to the value(s) in the table below. *a Component without harness connected (Cooler Compressor Assembly (Compressor Solenoid)) Standard Resistance Tester Connection Condition Specified Condition 1 (SOL-) - 2 (SOL+) 20°C (68°F) 10.1 to 11.1 ohms Result Proceed to OK NG Result: 2 NG REPLACE COOLER COMPRESSOR ASSEMBLY (COMPRESSOR SOLENOID). Refer to «REMOVAL [08/2013 - ]»(/toyota/corolla/xi-2012-2016/remont/automatic-hvac-system/#air-conditioning-system-service-information) Result: 1 OK See step 6
- CHECK HARNESS AND CONNECTOR (COOLER COMPRESSOR ASSEMBLY (COMPRESSOR SOLENOID) - BODY GROUND) Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition B8-1 (SOL-) - Body ground Always Below 1 ohms Result Proceed to OK NG Result: 2 NG REPAIR OR REPLACE HARNESS OR CONNECTOR Result: 1 OK See step 7
- CHECK HARNESS AND CONNECTOR (COOLER COMPRESSOR ASSEMBLY (COMPRESSOR SOLENOID) - AIR CONDITIONING AMPLIFIER ASSEMBLY) Disconnect the E37 air conditioning amplifier assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E37-2 (SOL+) - B8-2 (SOL+) Always Below 1 ohms E37-2 (SOL+) - Body ground Always 10 kohms or higher Result Result Proceed to NG A OK (When troubleshooting according to the Problem Symptoms Table) B OK (When troubleshooting according to the DTC) C Result: 1 A REPAIR OR REPLACE HARNESS OR CONNECTOR Result: 2 B PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE [08/2013 - ]»(ref-635442-S14519101662014070300000) Result: 3 C REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL [08/2013 - ]»(/toyota/corolla/xi-2012-2016/remont/automatic-hvac-system/#air-conditioning-system-service-information)
The air conditioning control assembly communicates with the air conditioning amplifier assembly via LIN communication.
If the LIN communication system malfunctions, the air conditioning amplifier assembly does not operate even if the air conditioning control assembly is operated.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory |
|---|---|---|---|---|
| B14B2 | Lost Communication with Front Panel LIN | Lost communication with air conditioning control assembly | Harness or connector between air conditioning control assembly and IG power source Harness or connector between air conditioning control assembly and body ground LIN communication system Air conditioning control assembly Air conditioning amplifier assembly | Memorized (10 sec. or more)*1 |
- *1: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.
Scheme 103
The cooler (room temp. sensor) thermistor is installed in the instrument panel to detect the cabin temperature, which is used to control the air conditioning system. The resistance of the cooler (room temp. sensor) thermistor changes in accordance with the cabin temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.
The air conditioning amplifier assembly applies a voltage (5 V) to the cooler (room temp. sensor) thermistor and reads voltage changes due to changes in the resistance of the cooler (room temp. sensor) thermistor.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory |
|---|---|---|---|---|
| B1411/11 | Room Temperature Sensor Circuit | Open or short in room temperature sensor circuit | Cooler (room temp. sensor) thermistor Harness or connector between cooler (room temp. sensor) thermistor and air conditioning amplifier assembly Air conditioning amplifier assembly | Memorized (4 sec. or more)*1 |
- *1: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.
Scheme 104
The thermistor assembly is installed in front of the cooler condenser assembly to detect the ambient temperature, which is used to control the air conditioning system. This sensor is connected to the combination meter assembly and detects fluctuations in the ambient temperature. This data is used for controlling the cabin temperature. The sensor sends a signal to the combination meter assembly. The resistance of the thermistor assembly changes in accordance with the ambient temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.
The combination meter assembly applies a voltage (5 V) to the thermistor assembly and reads voltage changes due to changes in the resistance of the thermistor assembly.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory |
|---|---|---|---|---|
| B1412/12 | Ambient Temperature Sensor Circuit | Open or short in ambient temperature sensor circuit | Thermistor assembly Harness or connector between thermistor assembly and combination meter assembly Air conditioning amplifier assembly Combination meter assembly CAN communication system | Memorized (4 sec. or more)*1 |
- *1: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.
Scheme 105
The No. 1 cooler thermistor is installed on the evaporator in the air conditioner unit to detect the temperature of the cooled air that has passed through the evaporator, which is used to control the air conditioning system. It sends signals to the air conditioning amplifier assembly. The resistance of the No. 1 cooler thermistor changes in accordance with the temperature of the cooled air that has passed through the evaporator. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.
The air conditioning amplifier assembly applies voltage (5 V) to the No. 1 cooler thermistor and reads voltage changes as the resistance of the No. 1 cooler thermistor changes. This sensor is used for frost prevention.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory |
|---|---|---|---|---|
| B1413/13 | Evaporator Temperature Sensor Circuit | Open or short in evaporator temperature sensor circuit | No. 1 cooler thermistor Air conditioning harness assembly Air conditioning amplifier assembly | Memorized (4 sec. or more)*1 |
- *1: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.
Scheme 106
The ECM sends the engine speed signal to the air conditioning amplifier assembly via CAN communication.
The air conditioning amplifier assembly reads the difference between compressor speed and engine speed. When the difference becomes too large, the air conditioning amplifier assembly determines that the compressor is locked, and turns the magnet clutch assembly off.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory |
|---|---|---|---|---|
| B1422/22 | Compressor Lock Sensor Circuit | Open or short in air conditioning lock sensor circuit (for 2ZR-FAE) | Magnet clutch assembly Cooler compressor assembly Harness or connector between cooler compressor assembly and air conditioning amplifier assembly Air conditioning amplifier assembly | Memorized (3 sec. or more)*1 |
- *1: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.
Scheme 107
This DTC is stored if refrigerant pressure on the high pressure side is extremely low (176 kPa (1.8 kgf/cm 2 , 26 psi) or less) or extremely high (3025 kPa (30.8 kgf/cm 2 , 439 psi) or more). The air conditioner pressure sensor, which is installed on the high pressure side pipe to detect refrigerant pressure, sends a refrigerant pressure signal to the air conditioning amplifier assembly. The air conditioning amplifier assembly converts this signal to a pressure value according to the sensor characteristics and uses it to control the compressor.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory |
|---|---|---|---|---|
| B1423/23 | Pressure Sensor Circuit | Open or short in air conditioner pressure sensor circuit Refrigerant pressure on high pressure side is extremely low (176 kPa (1.8 kgf/cm 2 , 26 psi) or less) or extremely high (3025 kPa (30.8 kgf/cm 2 , 439 psi) or more) | Air conditioner pressure sensor Harness or connector between air conditioner pressure sensor and air conditioning amplifier assembly Air conditioning amplifier assembly Cooler expansion valve (blocked, stuck) Cooler condenser assembly (blocked, deterioration of cooling capacity due to dirt) Cooler dryer (moisture in the refrigerant cycle cannot be absorbed) Cooling fan system (cooler condenser assembly cannot be cooled down) Air conditioning system (leaks, blocked) |
Scheme 108
The mode damper servo sub-assembly sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on these signals to move the mode damper servo sub-assembly to the appropriate position, which controls the air outlet switching.
The air conditioning amplifier assembly communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness assembly.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory |
|---|---|---|---|---|
| B1443/43 | Air Outlet Damper Control Servo Motor Circuit | Air outlet damper position sensor value does not change even if air conditioning amplifier assembly operates mode damper servo sub-assembly | Mode damper servo sub-assembly Air conditioning harness assembly Air conditioning amplifier assembly | Memorized (30 sec. or more)*1 |
- *1: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.
Scheme 109
The recirculation damper servo sub-assembly sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on these signals to move the air inlet mode selection recirculation damper servo sub-assembly to the appropriate position, which controls the air inlet mode (fresh, fresh/recirculation, and recirculation).
The air conditioning amplifier assembly communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness assembly.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory |
|---|---|---|---|---|
| B1442/42 | Air Inlet Damper Control Servo Motor Circuit | Air inlet damper position sensor value does not change even if air conditioning amplifier assembly operates recirculation damper servo sub-assembly | Recirculation damper servo sub-assembly Air conditioning harness assembly Air conditioning amplifier assembly | Memorized (30 sec. or more)*1 |
- *1: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.
Scheme 110
The air mix damper servo sub-assembly sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on these signals to move the air mix damper servo sub-assembly to the appropriate position. This adjusts the amount of air passing through the heater core after passing the evaporator and controls the temperature of the output air. The air conditioning amplifier assembly communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness assembly.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory |
|---|---|---|---|---|
| B1441/41 | Air Mix Damper Control Servo Motor Circuit (Passenger Side) | Air mix damper position sensor value does not change even if air conditioning amplifier assembly operates air mix damper servo sub-assembly | Air mix damper servo sub-assembly Air conditioning harness assembly Air conditioning amplifier assembly | Memorized (30 sec. or more)*1 |
- *1: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.
Scheme 111
The blower motor with fan sub-assembly is operated by signals from the air conditioning amplifier assembly. Blower motor speed signals are transmitted in accordance with changes in the duty ratio.
Scheme 112
When the air conditioning amplifier assembly is turned on, a magnet clutch on signal is sent from the MGC terminal of the air conditioning amplifier assembly. Then, the MGC relay turns on to operate the magnet clutch assembly.
Scheme 113
The air conditioning amplifier assembly sends operation signals to the PTC heater relays when the quick heater assembly operation conditions are met. Based on the signals from the air conditioning amplifier assembly, the PTC heater relays turn on, and power is supplied to the quick heater assembly installed in the air conditioning radiator assembly.
| Control ECU | Condition |
|---|---|
| Air Conditioning Amplifier Assembly | Engine running |
| ECO switch assembly off*1 | |
| Temperature setting: MAX HOT | |
| Ambient temperature: 10°C (50°F) or lower | |
| Engine coolant temperature: 75°C (167°F) or lower (2 quick heater relays operating) Engine coolant temperature: 80°C (176°F) or lower (1 quick heater relay operating) | |
| Light control switch assembly off | |
| Blower switch: On |
QUICK HEATER ASSEMBLY OPERATION CONDITION
- *1: w/ ECO Switch Assembly
Scheme 114
When the ECO switch assembly is turned on, the air conditioning amplifier assembly receives an ECO switch assembly ON signal and controls the air conditioning to enhance fuel efficiency.
Scheme 115
Scheme 116
- READ VALUE USING TECHSTREAM Connect the Techstream to the DLC3. Turn the ignition switch to ON. Turn the Techstream on. Enter the following menus: Body Electrical / Air Conditioner / Data List. Check the values by referring to the table below. Body Electrical > Air Conditioner > Data List Tester Display Measurement Item Range Normal Condition Diagnostic Note ECO Switch ECO switch assembly OFF or ON OFF: ECO switch assembly off (when switch is not pressed) ON: ECO switch assembly on (when switch is pressed) - Body Electrical > Air Conditioner > Data List Tester Display ECO Switch OK ECO switch assembly condition displayed on the Techstream changes with the actual switch operation. Result Proceed to OK NG Result: 1 OK PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE [08/2013 - ]»(ref-635442-S14519101662014070300000) Result: 2 NG See step 2
- INSPECT ECO SWITCH ASSEMBLY Remove the ECO switch assembly. Refer to «REMOVAL [08/2013 - ]»(ref-635611-S41864010602014070300000) Measure the resistance according to the value(s) in the table below. *a Component without harness connected (ECO Switch Assembly) Standard Resistance Tester Connection Condition Specified Condition 4 (ECU) - 1 (E) ECO switch assembly off (when switch is not pressed) 10 kohms or higher 4 (ECU) - 1 (E) ECO switch assembly on (when switch is pressed) Below 50 ohms Result Proceed to OK NG Result: 2 NG REPLACE ECO SWITCH ASSEMBLY. Refer to «REMOVAL [08/2013 - ]»(ref-635611-S41864010602014070300000) Result: 1 OK See step 3
- CHECK HARNESS AND CONNECTOR (ECO SWITCH ASSEMBLY - AIR CONDITIONING AMPLIFIER ASSEMBLY) Disconnect the E37 air conditioning amplifier assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E37-24 (ECOS) - E51-4 (ECU) Always Below 1 ohms E37-24 (ECOS) - Body ground Always 10 kohms or higher Result Proceed to OK NG Result: 2 NG REPAIR OR REPLACE HARNESS OR CONNECTOR Result: 1 OK See step 4
- CHECK HARNESS AND CONNECTOR (ECO SWITCH ASSEMBLY - BODY GROUND) Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E51-1 (E) - Body ground Always Below 1 ohms Result Proceed to OK NG Result: 1 OK REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL [08/2013 - ]»(/toyota/corolla/xi-2012-2016/remont/automatic-hvac-system/#air-conditioning-system-service-information) Result: 2 NG REPAIR OR REPLACE HARNESS OR CONNECTOR
Power source voltage is supplied to the air conditioning amplifier assembly when the ignition switch is ON. This power is used for operating the air conditioning amplifier assembly, servo motors, etc.
Scheme 117
The back-up power source circuit for the air conditioning amplifier assembly is shown below. Power is supplied even when the ignition switch is off. This power is used for diagnostic trouble code memory, etc.
Scheme 118
See also:
• REPLACEMENT [08/2013 - ]