Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001S4RI
Model Year Start: 2021 Model: Avalon Prod Date Range: [08/2020 -           ]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model): TERMINALS OF ECU; 2021 - 2022 MY Avalon [08/2020 -        ]

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
*: for 2GR-FKS

G36-1 (SG-1) - Body ground

LG - Body ground

Ground for cooler (room temp. sensor) thermistor

Always

Below 1 V

G36-2 (SG-2) - Body ground

W - Body ground

Ground for thermistor assembly

Always

Below 1 V

G36-3 (SG-4) - Body ground

L - Body ground

Ground for air conditioner pressure sensor

Always

Below 1 V

G36-6 (S5-3) - G36-3 (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

G36-9 (MGC) - G35-4 (GND)*

G - W-B

Magnetic clutch operation signal
  • Engine running
  • Blower switch: LO
  • A/C switch: Off

11 to 14 V
  • Engine running
  • Blower switch: LO
  • A/C switch: On

Below 1 V

G36-13 (TAM) - G36-2 (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

G36-14 (TR) - G36-1 (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

G36-20 (ECOS) - G35-4 (GND)

W - W-B

ECO switch assembly (electric parking brake switch assembly) signal
  • Engine switch on (IG)
  • ECO switch assembly (electric parking brake switch assembly): Off

11 to 14 V
  • Engine switch on (IG)
  • ECO switch assembly (electric parking brake switch assembly): On

Below 1 V

G36-21 (LOCK) - G36-2 (SG-2)*

B - W

A/C lock sensor signal
  • Engine running
  • Blower switch: LO
  • A/C switch: On

Pulse generation

(See waveform 1)

G36-24 (PRE) - G36-3 (SG-4)

W - L

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

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

Below 0.74 V
  • Engine running
  • 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

G35-1 (B) - G35-4 (GND)

LA-B - W-B

Power source (Back-up)

Always

11 to 14 V

G35-2 (IG+) - G35-4 (GND)

LA-GR - W-B

Power source (IG)

Engine switch on (IG)

11 to 14 V

Engine switch off

Below 1 V

G35-3 (SOL+) - G35-4 (GND)

R - W-B

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

Pulse generation

(See waveform 2)

G35-4 (GND) - Body ground

W-B - Body ground

Ground for main power supply

Always

Below 1 V

G35-6 (BLW) - G35-4 (GND)

LG - W-B

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

Pulse generation

(See waveform 3)

G35-11 (CANH) - G35-12 (CANL)

SB - W

CAN communication system

CAN communication is performed

Pulse generation

G35-14 (LIN1) - G35-4 (GND)

LG - W-B

LIN communication signal

Engine switch on (IG)

Pulse generation

(See waveform 4)

z8-2 (BUS G) - Body ground

B - Body ground

Ground for BUS IC

Always

Below 1 V

z8-3 (BUS) - z8-2 (BUS G)

L - B

BUS IC control signal

Engine switch on (IG)

Pulse generation

(See waveform 5)

z8-4 (B BUS) - z8-2 (BUS G)

R - B

Power supply for BUS IC

Engine switch off

11 to 14 V

z8-5 (SGA) - Body ground

GR - Body ground

Ground for No. 1 cooler thermistor

Always

Below 1 V

z8-6 (TEA) - z8-5 (SGA)

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.

G36-21 (LOCK) - G36-2 (SG-2)

Tool Setting

200 mV/DIV., 10 ms./DIV.

Condition
  • Engine running
  • Blower switch: LO
  • A/C switch: On

(b) Waveform 2:

Item

Content

Terminal No.

G35-3 (SOL+) - G35-4 (GND)

Tool Setting

5 V/DIV., 500 μs./DIV.

Condition
  • Engine running
  • Blower switch: LO
  • A/C switch: On

(c) Waveform 3:

Item

Content

Terminal No.

G35-6 (BLW) - G35-4 (GND)

Tool Setting

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

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

(d) Waveform 4:

Item

Content

Terminal No.

G35-14 (LIN1) - G35-4 (GND)

Tool Setting

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

Condition

Engine switch on (IG)

(e) Waveform 5:

Item

Content

Terminal No.

z8-3 (BUS) - z8-2 (BUS G)

Tool Setting

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

Condition

Engine switch on (IG)

CHECK AIR CONDITIONING CONTROL PANEL (RADIO AND DISPLAY RECEIVER 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

G20-2 (IG+) - G20-6 (GND)

GR - W-B

Power source (IG)

Engine switch off

Below 1 V

Engine switch on (IG)

11 to 14 V

G20-3 (+B) - G20-6 (GND)

L - W-B

Power source (Back-up)

Engine switch off

11 to 14 V

G20-6 (GND) - Body ground

W-B - Body ground

Ground for air conditioning control panel (radio and display receiver assembly)

Always

Below 1 V

G20-8 (LIN1) - Body ground

LG - Body ground

LIN communication signal

Engine switch on (IG)

Pulse generation

(See waveform)

G20-10 (ACC) - G20-6 (GND)

P - W-B

Power source (ACC)

Engine switch off

Below 1 V

Engine switch ACC

11 to 14 V

G20-11 (ILL+) - Body ground

W - Body ground

Illumination signal

Taillight off

Below 1 V

Taillight on

11 to 14 V

G20-15 (ILL-) - Body ground

B - Body ground

Illumination signal

Always

Below 1 V

(a) Waveform:

Item

Content

Terminal No.

G20-8 (LIN1) - Body ground

Tool Setting

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

Condition

Engine switch on (IG)