Last Modified: 07-31-2024 6.11:8.1.0 Doc ID: RM100000001NLXY
Model Year Start: 2021 Model: Corolla Prod Date Range: [04/2020 - 06/2021]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): TERMINALS OF ECU; 2021 MY Corolla Corolla HV [04/2020 - 06/2021]

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) - Body ground

R - Body ground

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

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

0.64 to 0.87 V

I48-3 (SG-1) - Body ground

W - Body ground

Ground for cooler (room temp. sensor) thermistor

Always

Below 1 V

I48-5 (TR) - I49-17 (GND)

B - W-B

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

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

0.64 to 0.87 V

I48-6 (PRE) - I49-17 (GND)

L - W-B

Air conditioner pressure sensor signal
  • Power switch on (READY)
  • Air conditioning system operating
  • Refrigerant pressure: Abnormal pressure (more than 3025 kPaG (30.8 kgf/cm2, 439 psi)*1, more than 2812 kPaG (28.7 kgf/cm2, 408 psi)*2)

4.73 V or higher
  • Power switch on (READY)
  • Air conditioning system operating
  • Refrigerant pressure: Abnormal pressure (less than 176 kPaG (1.8 kgf/cm2, 26 psi)*1, less than 196 kPaG (2.0 kgf/cm2, 28 psi) or less*2)

Below 0.62 V
  • Power switch on (READY)
  • 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)*1, less than 2812 kPaG (28.7 kgf/cm2, 408 psi) and more than 196 kPaG (2.0 kgf/cm2, 28 psi)*2)

0.62 to 4.73 V*4

I48-11 (S5-3) - I49-17 (GND)

B - W-B

Power supply for air conditioner pressure sensor

Power switch on (IG)

4.75 to 5.25 V

Power switch off

Below 1 V

I48-14 (SG-2) - Body ground

BR - Body ground

Ground for thermistor assembly

Always

Below 1 V

I48-15 (SG-4) - Body ground

G - Body ground

Ground for air conditioner pressure sensor

Always

Below 1 V

I48-16 (PTC2) - I49-17 (GND)*3

B - W-B

Quick heater assembly operation signal
  • Power switch on (READY)
  • ECO switch assembly (air conditioning control assembly): Off
  • Temperature setting: MAX HOT
  • Ambient temperature: 10°C (50°F) or lower
  • Engine coolant temperature: 65°C (149°F) or lower
  • Blower switch: On

Below 1 V
  • Power switch on (READY)
  • ECO switch assembly (air conditioning control assembly): Off
  • Temperature setting: MAX HOT
  • Ambient temperature: 10°C (50°F) or lower
  • Engine coolant temperature: 65°C (149°F) or lower
  • Blower switch: Off

11 to 14 V

I48-17 (PTC3) - I49-17 (GND)*3

BR - W-B

Quick heater assembly operation signal
  • Power switch on (READY)
  • ECO switch assembly (air conditioning control assembly): Off
  • Temperature setting: MAX HOT
  • Ambient temperature: 10°C (50°F) or lower
  • Engine coolant temperature: 60°C (140°F) or lower
  • Blower switch: On

Below 1 V
  • Power switch on (READY)
  • ECO switch assembly (air conditioning control assembly): Off
  • Temperature setting: MAX HOT
  • Ambient temperature: 10°C (50°F) or lower
  • Engine coolant temperature: 60°C (140°F) or lower
  • Blower switch: Off

11 to 14 V

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

W - G

CAN communication system

CAN communication is performed

Pulse generation

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

LG - W-B

Power source (Back-up)

Power switch off

11 to 14 V

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

SB - W-B

Power source (IG)

Power switch on (IG)

11 to 14 V

Power switch off

Below 1 V

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

V - W-B

LIN communication signal

Power 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

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

W - W-B

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

Pulse generation

(See waveform 1)

I49-23 (PTC1) - I49-17 (GND)*3

W - W-B

Quick heater assembly operation signal
  • Power switch on (READY)
  • ECO switch assembly (air conditioning control assembly): Off
  • Temperature setting: MAX HOT
  • Ambient temperature: 10°C (50°F) or lower
  • Engine coolant temperature: 70°C (158°F) or lower
  • Blower switch: On

Below 1 V
  • Power switch on (READY)
  • ECO switch assembly (air conditioning control assembly): Off
  • Temperature setting: MAX HOT
  • Ambient temperature: 10°C (50°F) or lower
  • Engine coolant temperature: 70°C (158°F) or lower
  • Blower switch: Off

11 to 14 V

z1-2 (BUSG) - Body ground

-

Ground for BUS IC

Always

Below 1 V

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

-

BUS IC control signal

Power switch on (IG)

Pulse generation

(See waveform 3)

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

-

Power supply for BUS IC

Power switch off

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
  • Power switch on (IG)
  • Evaporator temperature: 0°C (32°F)

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

0.9 to 1.3 V
  • *1: for HFC-134a (R134a)
  • *2: for HFO-1234yf (R1234yf)
  • *3: w/ PTC Heater
  • *4: While sensor voltage is 5 V.

(a) Waveform 1:

Item

Content

Terminal No.

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

Tool Setting

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

Condition
  • Power 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

Power 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

Power switch on (IG)

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

V - Body ground

LIN communication signal

Power switch on (IG)

Pulse generation

(See waveform)

I37-8 (ILL+) - Body ground

P - Body ground

Illumination signal

Taillight off

Below 1 V

Taillight on

11 to 14 V

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

LG - W-B

Power source (IG)

Power switch off

Below 1 V

Power 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

W - 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

Power switch on (IG)

CHECK HYBRID VEHICLE CONTROL ECU

for NICKEL METAL HYDRIDE BATTERY: Click here 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): TERMINALS OF ECU

for LITHIUM-ION BATTERY: Click here 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with P610): TERMINALS OF ECU