Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001CNZV
Model Year Start: 2019 Model: GR Corolla Prod Date Range: [06/2018 - 01/2019]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model with Automatic Air Conditioning System): TERMINALS OF ECU; 2019 MY Corolla Corolla Hatchback GR Corolla [06/2018 - 01/2019]

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.

Terminal No.

(Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

I48-1 (TAM) - I48-14 (SG-2)

R - W

Thermistor assembly signal
  • Engine switch on (IG)
  • Ambient temperature: 25°C (77°F)

1.05 to 1.45 V
  • Engine switch on (IG)
  • Ambient temperature: 40°C (104°F)

0.64 to 0.87 V

I48-3 (SG-1) - Body ground

LG - Body ground

Ground for cooler (room temp. sensor) thermistor

Always

Below 1 V

I48-5 (TR) - I48-3 (SG-1)

GR - LG

Cooler (room temp. sensor) thermistor signal
  • Engine switch on (IG)
  • Cabin temperature: 25°C (77°F)

1.05 to 1.45 V
  • Engine switch on (IG)
  • Cabin temperature: 40°C (104°F)

0.64 to 0.87 V

I48-6 (PRE) - I48-15 (SG-4)

W - L

Air conditioner pressure sensor signal
  • Engine switch on (IG)
  • Air conditioning system operating
  • Refrigerant pressure: Abnormal pressure (more than 3025 kPaG (30.8 kgf/cm2, 439 psi))

4.61 V or higher
  • Engine switch on (IG)
  • Air conditioning system operating
  • Refrigerant pressure: Abnormal pressure (less than 176 kPaG (1.8 kgf/cm2, 26 psi))

Below 0.74 V
  • Engine switch on (IG)
  • Air conditioning system operating
  • Refrigerant pressure: Normal pressure (less than 3025 kPaG (30.8 kgf/cm2, 439 psi) and more than 176 kPaG (1.8 kgf/cm2, 26 psi))

0.74 to 4.61 V

I48-11 (S5-3) - I48-15 (SG-4)

GR - L

Power supply for air conditioner pressure sensor

Engine switch on (IG)

4.75 to 5.25 V

Engine switch off

Below 1 V

I48-14 (SG-2) - Body ground

W - Body ground

Ground for thermistor assembly

Always

Below 1 V

I48-15 (SG-4) - Body ground

L - Body ground

Ground for air conditioner pressure sensor

Always

Below 1 V

I49-1 (CANH) - I49-2 (CANL)

SB - W

CAN communication system

CAN communication is performed

Pulse generation

I49-5 (B) - I49-17 (GND)

LA-B - W-B

Power source (Back-up)

Always

11 to 14 V

I49-6 (IG+) - I49-17 (GND)

LA-GR - W-B

Power source (IG)

Engine switch on (IG)

11 to 14 V

Engine switch off

Below 1 V

I49-7 (LIN1) - I49-17 (GND)

BE - W-B

LIN communication signal

Engine switch on (IG)

Pulse generation

(See waveform 2)

I49-17 (GND) - Body ground

W-B - Body ground

Ground for main power supply

Always

Below 1 V

I49-18 (SOL+) - I49-17 (GND)

B - W-B

Compressor solenoid operation signal
  • Engine running
  • Blower switch: LO
  • A/C switch: On

Pulse generation

(See waveform 4)

I49-21 (BLW) - I49-17 (GND)

LG - W-B

Blower motor speed control signal
  • Engine switch on (IG)
  • Blower switch: LO

Pulse generation

(See waveform 1)

z1-2 (BUSG) - Body ground

-

Ground for BUS IC

Always

Below 1 V

z1-3 (BUS) - z1-2 (BUSG)

-

BUS IC control signal

Engine switch on (IG)

Pulse generation

(See waveform 3)

z1-4 (BUSB) - z1-2 (BUSG)

-

Power supply for BUS IC

Always

11 to 14 V

z1-5 (SG-3) - Body ground

GR - Body ground

Ground for No. 1 cooler thermistor

Always

Below 1 V

z1-6 (TE) - z1-5 (SG-3)

GR - GR

No. 1 cooler thermistor signal
  • Engine switch on (IG)
  • Evaporator temperature: 0°C (32°F)

1.7 to 2.1 V
  • Engine switch on (IG)
  • Evaporator temperature: 15°C (59°F)

0.9 to 1.3 V

(a) Waveform 1:

Item

Content

Terminal No.

I49-21 (BLW) - I49-17 (GND)

Tool Setting

2 V/DIV., 1 ms./DIV.

Condition
  • Engine switch on (IG)
  • Blower switch: LO

(b) Waveform 2:

Item

Content

Terminal No.

I49-7 (LIN1) - I49-17 (GND)

Tool Setting

2 V/DIV., 20 ms./DIV.

Condition

Engine switch on (IG)

(c) Waveform 3:

Item

Content

Terminal No.

z1-3 (BUS) - z1-2 (BUSG)

Tool Setting

2 V/DIV., 2 ms./DIV.

Condition

Engine switch on (IG)

(d) Waveform 4:

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

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)

Wiring Color

Terminal Description

Condition

Specified Condition

I37-7 (LIN1) - Body ground

LG - Body ground

LIN communication signal

Engine switch on (IG)

Pulse generation

(See waveform)

I37-8 (ILL+) - Body ground

W - Body ground

Illumination signal

Taillight off

Below 1 V

Taillight on

11 to 14 V

I37-9 (IG+) - I37-13 (GND)

GR - W-B

Power source (IG)

Engine switch off

Below 1 V

Engine switch on (IG)

11 to 14 V

I37-13 (GND) - Body ground

W-B - Body ground

Ground for air conditioning control assembly

Always

Below 1 V

I37-14 (ILL-) - Body ground

B - 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

Engine switch on (IG)