Toyota Corolla Cross: Terminals Of Ecu

Toyota Corolla Cross (2022-2024) Service Manual / Vehicle Interior / Heating / Air Conditioning / Air Conditioning System (for Hev Model) / Terminals Of Ecu

TERMINALS OF ECU

CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

HINT:

Check from the rear of the connector while it is connected to the air conditioning amplifier assembly.
Make sure to wait at least 2 minutes after turning the ignition switch off before performing an ECU terminal inspection.

Terminal No. (Symbol)	Terminal Description	Condition	Specified Condition
I48-1 (TAM) - Body ground	Thermistor assembly signal	Ignition switch ON Ambient temperature: 25°C (77°F)	1.05 to 1.45 V
I48-1 (TAM) - Body ground	Thermistor assembly signal	Ignition switch ON Ambient temperature: 40°C (104°F)	0.64 to 0.87 V
I48-3 (SG-1) - Body ground	Ground for cooler thermistor (room temperature sensor)	Always	Below 1 V
I48-5 (TR) - I49-17 (GND)	Cooler thermistor (room temperature sensor) signal	Ignition switch ON Cabin temperature: 25°C (77°F)	1.05 to 1.45 V
I48-5 (TR) - I49-17 (GND)	Cooler thermistor (room temperature sensor) signal	Ignition switch ON Cabin temperature: 40°C (104°F)	0.64 to 0.87 V
I48-6 (PRE) - I49-17 (GND)	Air conditioner pressure sensor signal	Ignition switch ON (READY) Air conditioning system operating Refrigerant pressure: Abnormal pressure (more than 2812 kPa (28.7 kgf/cm2, 408 psi)	4.61 V or higher*1
		Ignition switch ON (READY) Air conditioning system operating Refrigerant pressure: Abnormal pressure (less than 196 kPa (2.0 kgf/cm2, 28 psi))	Below 0.74 V*1
		Ignition switch ON (READY) Air conditioning system operating Refrigerant pressure: Normal pressure (less than 2812 kPa (28.7 kgf/cm2, 408 psi) and more than 196 kPa (2.0 kgf/cm2, 28 psi))	0.74 to 4.61 V*1
I48-11 (S5-3) - I49-17 (GND)	Power supply for air conditioner pressure sensor	Ignition switch ON	4.75 to 5.25 V
I48-11 (S5-3) - I49-17 (GND)	Power supply for air conditioner pressure sensor	Ignition switch off	Below 1 V
I48-14 (SG-2) - Body ground	Ground for thermistor assembly	Always	Below 1 V
I48-15 (SG-4) - Body ground	Ground for air conditioner pressure sensor	Always	Below 1 V
I49-1 (CANL) - I49-2 (CANH)	CAN communication system	CAN communication is performed	Pulse generation
I49-5 (B) - I49-17 (GND)	Power source (Back-up)	Always	11 to 14 V
I49-6 (IG+) - I49-17 (GND)	Power source (IG)	Ignition switch ON	11 to 14 V
I49-6 (IG+) - I49-17 (GND)	Power source (IG)	Ignition switch off	Below 1 V
I49-7 (LIN1) - I49-17 (GND)	LIN communication signal	Ignition switch ON	Pulse generation (See waveform 1)
I49-17 (GND) - Body ground	Ground for main power supply	Always	Below 1 V
I49-18 (SOL+) - I49-17 (GND)	Compressor solenoid operation signal	Engine running Blower switch: LO A/C switch: On	Pulse generation (See waveform 2)
I49-21 (BLW) - I49-17 (GND)	Blower motor speed control signal	Ignition switch ON Blower switch: LO	Pulse generation (See waveform 3)
z1-2 (BUS G) - Body ground	Ground for BUS IC	Always	Below 1 V
z1-3 (BUS) - z1-2 (BUS G)	BUS IC control signal	Ignition switch ON	Pulse generation (See waveform 4)
z1-4 (B BUS) - z1-2 (BUS G)	Power supply for BUS IC	Always	11 to 14 V
z1-5 (SGA) - Body ground	Ground for No. 1 cooler thermistor	Always	Below 1 V
z1-6 (TEA) - z1-5 (SGA)	No. 1 cooler thermistor signal	Ignition switch ON Evaporator temperature: 0°C (32°F)	1.7 to 2.1 V
z1-6 (TEA) - z1-5 (SGA)	No. 1 cooler thermistor signal	Ignition switch ON Evaporator temperature: 15°C (59°F)	0.9 to 1.3 V

*1: While sensor voltage is 5 V.

(a) Waveform 1:

Item	Content
Terminal No.	I49-7 (LIN1) - I49-17 (GND)
Tool Setting	2 V/DIV., 20 ms./DIV.
Condition	Ignition switch ON

(b) Waveform 2:

Item	Content
Terminal No.	I49-18 (SOL+) - I49-17 (GND)
Tool Setting	5 V/DIV., 500 μs./DIV.
Condition	Engine running Blower switch: LO A/C switch: On

Item	Content
Terminal No.	I49-21 (BLW) - I49-17 (GND)
Tool Setting	2 V/DIV., 1 ms./DIV.
Condition	Ignition switch ON Blower switch: LO

(d) Waveform 4:

Item	Content
Terminal No.	z1-3 (BUS) - z1-2 (BUS G)
Tool Setting	2 V/DIV., 2 ms./DIV.
Condition	Ignition switch ON

CHECK AIR CONDITIONING CONTROL ASSEMBLY

HINT:

Check from the rear of the connector while it is connected to the air conditioning control assembly.

Terminal No. (Symbol)	Terminal Description	Condition	Specified Condition
I37-7 (LIN1) - Body ground	LIN communication signal	Ignition switch ON	Pulse generation (See waveform)
I37-8 (ILL+) - Body ground	Illumination signal	Taillight off	Below 1 V
I37-8 (ILL+) - Body ground	Illumination signal	Taillight on	11 to 14 V
I37-9 (IG+) - I37-13 (GND)	Power source (IG)	Ignition switch off	Below 1 V
I37-9 (IG+) - I37-13 (GND)	Power source (IG)	Ignition switch ON	11 to 14 V
I37-13 (GND) - Body ground	Ground for air conditioning control assembly	Always	Below 1 V
I37-14 (ILL-) - Body ground	Illumination signal	Always	Below 1 V

(a) Waveform:

Item	Content
Terminal No.	I37-7 (LIN1) - Body ground
Tool Setting	2 V/DIV., 20 ms./DIV.
Condition	Ignition switch ON

SEE MORE:

Operation not Accepted Even If Air Conditioning Switch is Operated

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Toyota Corolla Cross: Terminals Of Ecu

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Data List / Active Test

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Operation not Accepted Even If Air Conditioning Switch is Operated

IG Circuit Short to Ground (B227111)