Last Modified: 11-20-2023 6.11:8.1.0 Doc ID: RM100000001E5Z8
Model Year Start: 2019 Model: Camry Prod Date Range: [08/2018 - 10/2020]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System): TERMINALS OF ECU; 2019 - 2020 MY Camry [08/2018 - 10/2020]

TERMINALS OF ECU

CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

*A

w/o Seat Heater

*B

w/ Seat Heater

*C

for Dual Type

*D

for Single Type

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)

Wiring Color

Terminal Description

Condition

Specified Condition

K55-1 (SG-1) - Body ground

LG - Body ground

Ground for cooler (room temp. sensor) thermistor

Always

Below 1 V

K55-2 (SG-2) - Body ground

W - Body ground

Ground for thermistor assembly

Always

Below 1 V

K55-3 (SG-4) - Body ground

L - Body ground

Ground for air conditioner pressure sensor

Always

Below 1 V

K55-6 (S5-3) - K55-3 (SG-4)

GR - L

Power supply for air conditioner pressure sensor

Ignition switch ON

4.75 to 5.25 V

Ignition switch off

Below 1 V

K55-9 (MGC) - K54-9 (GND)*3

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

K55-13 (TAM) - K55-2 (SG-2)

R - W

Thermistor assembly signal
  • Ignition switch ON
  • Ambient temperature: 25°C (77°F)

1.05 to 1.45 V
  • Ignition switch ON
  • Ambient temperature: 40°C (104°F)

0.64 to 0.87 V

K55-14 (TR) - K55-1 (SG-1)

GR - LG

Cooler (room temp. sensor) thermistor signal
  • Ignition switch ON
  • Cabin temperature: 25°C (77°F)

1.05 to 1.45 V
  • Ignition switch ON
  • Cabin temperature: 40°C (104°F)

0.64 to 0.87 V

K55-20 (ECOS) - K54-9 (GND)*4

W - W-B

ECO switch assembly (electric parking brake switch assembly) signal
  • Ignition switch ON
  • ECO switch assembly (electric parking brake switch assembly): off

11 to 14 V
  • Ignition switch ON
  • ECO switch assembly (electric parking brake switch assembly): On

Below 1 V

K55-21 (LOCK) - K55-2 (SG-2)*3

B - W

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

Pulse generation

(See waveform 1)

K55-24 (PRE) - K55-3 (SG-4)

W - L

Air conditioner pressure sensor signal
  • Engine running
  • Air conditioning system operating
  • for HFC-134a(R134a):

    Refrigerant pressure: Abnormal pressure (more than 3025 kPaG (30.8 kgf/cm2, 439 psi))

  • for HFO-1234yf(R1234yf):

    Refrigerant pressure: Abnormal pressure (more than 2812 kPaG (28.7 kgf/cm2, 408 psi))

4.61 V or higher
  • Engine running
  • Air conditioning system operating
  • for HFC-134a(R134a):

    Refrigerant pressure: Abnormal pressure (less than 176 kPaG (1.8 kgf/cm2, 26 psi))

  • for HFO-1234yf(R1234yf):

    Refrigerant pressure: Abnormal pressure (less than 196 kPaG (2.0 kgf/cm2, 28 psi))

Below 0.74 V
  • Engine running
  • Air conditioning system operating
  • for HFC-134a(R134a):

    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))

  • for HFO-1234yf(R1234yf):

    Refrigerant pressure: Normal pressure (less than 2812 kPaG (28.7 kgf/cm2, 408 psi) and more than 196 kPaG (2.0 kgf/cm2, 28 psi))

0.74 to 4.61 V

K54-1 (B) - K54-4 (GND)

LA-B - W-B

Power source (Back-up)

Always

11 to 14 V

K54-2 (IG+) - K54-4 (GND)

LA-GR - W-B

Power source (IG)

Ignition switch ON

11 to 14 V

Ignition switch off

Below 1 V

K54-3 (SOL+) - K54-4 (GND)

R - W-B

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

Pulse generation

(See waveform 2)

K54-4 (GND) - Body ground

W-B - Body ground

Ground for main power supply

Always

Below 1 V

K54-6 (BLW) - K54-4 (GND)

LG - W-B

Blower motor speed control signal
  • Ignition switch ON
  • Blower switch: LO

Pulse generation

(See waveform 3)

K54-11 (CANH) - K54-12 (CANL)

SB - W

CAN communication system

CAN communication is performed

Pulse generation

K54-14 (LIN1) - K54-4 (GND)

LG - W-B*6,*7,*10

LIN communication signal

Ignition switch ON

Pulse generation

(See waveform 4)

BE - W-B*5,*7 or *7,*9

LIN communication signal

Ignition switch ON

Pulse generation

(See waveform 4)

B - W-B*5,*8

LIN communication signal

Ignition switch ON

Pulse generation

(See waveform 4)

z28-2 (BUS G) - Body ground*1

-

Ground for BUS IC

Always

Below 1 V

z28-3 (BUS) - z28-2 (BUS G)*1

-

BUS IC control signal

Ignition switch ON

Pulse generation

(See waveform 5)

z28-4 (B BUS) - z28-2 (BUS G)*1

-

Power supply for BUS IC

Ignition switch off

11 to 14 V

z28-5 (SG) - Body ground*1

GR - Body ground

Ground for No. 1 cooler thermistor

Always

Below 1 V

z28-6 (TE) - z28-5 (SG)*1

GR - GR

No. 1 cooler thermistor signal
  • Ignition switch ON
  • Evaporator temperature: 0°C (32°F)

1.7 to 2.1 V
  • Ignition switch ON
  • Evaporator temperature: 15°C (59°F)

0.9 to 1.3 V

z29-2 (1A) - Body ground*2

-

Ground for BUS IC

Always

Below 1 V

z29-3 (2A) - z29-2 (1A)*2

-

BUS IC control signal

Ignition switch ON

Pulse generation

(See waveform 5)

z29-4 (3A) - z29-2 (1A)*2

-

Power supply for BUS IC

Ignition switch off

11 to 14 V

z29-5 (4A) - Body ground*2

GR - Body ground

Ground for No. 1 cooler thermistor

Always

Below 1 V

z29-6 (5A) - z29-5 (4A)*2

GR - GR

No. 1 cooler thermistor signal
  • Ignition switch ON
  • Evaporator temperature: 0°C (32°F)

1.7 to 2.1 V
  • Ignition switch ON
  • Evaporator temperature: 15°C (59°F)

0.9 to 1.3 V
  • *1: for Dual Type
  • *2: for Single Type
  • *3: for 2GR-FKS
  • *4: w/ Electric Parking Brake System
  • *5: w/ Seat Heater
  • *6: w/o Seat Heater
  • *7: for 7 Inch Display
  • *8: for 8 Inch Display
  • *9: for TMC Made
  • *10: for TMMK Made

(a) Waveform 1:

Item

Content

Terminal No.

K55-21 (LOCK) - K55-2 (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.

K54-3 (SOL+) - K54-4 (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.

K54-6 (BLW) - K54-4 (GND)

Tool Setting

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

Condition
  • Ignition switch ON
  • Blower switch: LO

(d) Waveform 4:

Item

Content

Terminal No.

K54-14 (LIN1) - K54-4 (GND)

Tool Setting

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

Condition

Ignition switch ON

(e) Waveform 5:

Item

Content

Terminal No.

z28-3 (BUS) - z28-2 (BUS G)*1

z29-3 (2A) - z29-2 (1A)*2

Tool Setting

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

Condition

Ignition switch ON
  • *1: for Dual Type
  • *2: for Single Type

CHECK AIR CONDITIONING CONTROL PANEL (RADIO AND DISPLAY RECEIVER ASSEMBLY) (for 8 Inch Display)

HINT:

Check from the rear of the connector while it is connected to the air conditioning control panel (radio and display receiver assembly).

Terminal No.

(Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

h1-2 (IG1) - h1-6 (GND)

SB - W-B

Power source (IG)

Ignition switch off

Below 1 V

Ignition switch ON

11 to 14 V

h1-3 (+B) - h1-6 (GND)

G - W-B

Power source (Back-up)

Ignition switch off

11 to 14 V

h1-6 (GND) - Body ground

W-B - Body ground

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

Always

Below 1 V

h1-10 (ACC) - h1-6 (GND)

R - W-B

Power source (ACC)

Ignition switch off

Below 1 V

Ignition switch ACC

11 to 14 V

h1-11 (ILL+) - Body ground

W - Body ground

Illumination signal

Light control switch in off position

Below 1 V

Light control switch in tail or head position

11 to 14 V

h1-15 (ILL-) - Body ground

L - Body ground

Illumination signal

Always

Below 1 V

CHECK AIR CONDITIONING CONTROL ASSEMBLY (for 7 Inch Display)

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

K26-2 (IG+) - K26-6 (GND)

GR - W-B

Power source (IG)

Ignition switch off

Below 1 V

Ignition switch ON

11 to 14 V

K26-6 (GND) - Body ground

W-B - Body ground

Ground for air conditioning control assembly

Always

Below 1 V

K26-9 (LIN1) - Body ground

LG - Body ground

LIN communication signal

Ignition switch ON

Pulse generation

(See waveform)

K26-11 (ILL+) - Body ground

W - Body ground

Illumination signal

Light control switch in off position

Below 1 V

Light control switch in tail or head position

11 to 14 V

K26-15 (ILL-) - Body ground

B - Body ground

Illumination signal

Always

Below 1 V

(a) Waveform:

Item

Content

Terminal No.

K26-9 (LIN1) - Body ground

Tool Setting

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

Condition

Ignition switch ON