Toyota Yaris: Air Conditioning System / Terminals Of Ecu

Toyota Yaris XP210 (2020-2025) Reapir and Service Manual / Vehicle Interior / Heating / Air Conditioning / Air Conditioning System / Terminals Of Ecu

TERMINALS OF ECU

CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

(a) Check air conditioning amplifier assembly.

(1) Disconnect the H24 air conditioning amplifier assembly connector.

(2) Measure the voltage and resistance according to the value(s) in the table below.

Standard:

Terminal No.

(Symbol)

Terminal Description

Condition

Specified Condition

H24-5 (B) - H24-17 (GND)

Power source

Always

11 to 14 V

H24-6 (IG+) - H24-17 (GND)

Power source (IG)

Ignition switch ON

11 to 14 V

Ignition switch off

Below 1 V

H24-17 (GND) - Body ground

Ground for main power supply

Always

Below 1 Ω

(3) Connect the H24 air conditioning amplifier assembly connector.

(4) Measure the voltage, resistance and waveform according to the value(s) in the table below.

Standard:

Terminal No.

(Symbol)

Terminal Description

Condition

Specified Condition

H25-3 (SG-1) - Body ground

Ground for cooler thermistor (room temperature sensor)

Always

Below 1 Ω

H25-5 (TR) - H24-17 (GND)

Cooler thermistor (room temperature sensor) signal

  • Ignition switch ON
  • Cabin temperature: 25°C (77°F)

1.05 to 1.45 V

H25-6 (PRE) - H24-17 (GND)

Air conditioner pressure sensor signal

  • Ignition switch ON
  • Air conditioning system operating
  • Refrigerant pressure: Normal pressure (less than 3.025 MPaG [30.8 kgf/cm2, 439 psi]) and 0.176 MPaG [1.8 kgf/cm2, 26 psi] or higher)

Less than 4.73 V and 0.62 V or higher*1

  • Ignition switch ON
  • Air conditioning system operating
  • Refrigerant pressure: Abnormal pressure (3.025 MPaG [30.8 kgf/cm2, 439 psi] or higher)

4.73 V or higher*1

  • Ignition switch ON
  • Air conditioning system operating
  • Refrigerant pressure: Abnormal pressure (less than 0.176 MPaG [1.8 kgf/cm2, 26 psi])

Less than 0.62 V*1

H25-11 (S5-3) - H24-17 (GND)

Power supply for air conditioner pressure sensor

Ignition switch ON

4.75 to 5.25 V

Ignition switch off

Below 1 V

H25-15 (SG-4) - Body ground

Ground for air conditioner pressure sensor

Always

Below 1 Ω

H24-1 (CANL) - H24-17 (GND)

CAN communication system

Ignition switch ON

Pulse generation

H24-2 (CANH) - H24-17 (GND)

CAN communication system

Ignition switch ON

Pulse generation

H24-7 (LIN1) - H24-17 (GND)

LIN communication signal

Ignition switch ON

Pulse generation

(See waveform 1)

H24-18 (SOL+) - H24-17 (GND)

Compressor solenoid operation signal

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

Pulse generation

(See waveform 2)

H24-21 (BLW) - H24-17 (GND)

Blower motor speed control signal

  • Ignition switch ON
  • Blower switch: LO

Pulse generation

(See waveform 3)

h6-2 (BUSG) - Body ground

Ground for BUS IC

Always

Below 1 Ω

h6-3 (BUS) - h6-2 (BUSG)

BUS IC control signal

Ignition switch ON

Pulse generation

(See waveform 4)

h6-4 (BUSB) - h6-2 (BUSG)

Power supply for BUS IC

Always

11 to 14 V

h6-5 (SG-3) - Body ground

Ground for No. 1 cooler thermistor

Always

Below 1 Ω

h6-6 (TE) - h6-5 (SG-3)

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: While sensor voltage is 5 V.

(b) Waveform 1:

Item

Content

Terminal No.

H24-7 (LIN1) - H24-17 (GND)

Tool Setting

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

Condition

Ignition switch ON

(c) Waveform 2:

Item

Content

Terminal No.

H24-18 (SOL+) - H24-17 (GND)

Tool Setting

5 V/DIV., 500 μs./DIV.

Condition

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

(d) Waveform 3:

Item

Content

Terminal No.

H24-21 (BLW) - H24-17 (GND)

Tool Setting

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

Condition

  • Ignition switch ON
  • Blower switch: LO

HINT:

The waveform varies with the blower speed.

(e) Waveform 4:

Item

Content

Terminal No.

h6-3 (BUS) - h6-2 (BUSG)

Tool Setting

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

Condition

Ignition switch ON

CHECK AIR CONDITIONING CONTROL ASSEMBLY

(a) Check air conditioning control assembly.

(1) Disconnect the H31 air conditioning control assembly connector.

(2) Measure the voltage, resistance and waveform according to the value(s) in the table below.

Standard:

Terminal No.

(Symbol)

Terminal Description

Condition

Specified Condition

H31-7 (LIN1) - Body ground

LIN communication signal

Ignition switch ON

Pulse generation

(See waveform 1)

H31-8 (ILL+) - Body ground

Illumination signal

Taillight off

Below 1 V

Taillight on

11 to 14 V

H31-9 (IG+) - H31-13 (GND)

Power source (IG)

Ignition switch off

Below 1 V

Ignition switch ON

10.5 to 16 V

H31-13 (GND) - Body ground

Ground for air conditioning control assembly

Always

Below 1 Ω

H31-14 (ILL-) - Body ground

Illumination signal

Always

Below 1 V

(b) Waveform 1:

Item

Content

Terminal No.

H31-7 (LIN1) - Body ground

Tool Setting

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

Condition

Ignition switch ON

    Problem Symptoms Table

    PROBLEM SYMPTOMS TABLE NOTICE: Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table...

    Dtc Check / Clear

    D..

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    No special break-in is necessary, but a few precautions in the first 600 miles (1,000 km) may add to the performance, economy, and life of the vehicle.

    Do not race the engine. Do not maintain one constant speed, either slow or fast, for a long period of time. Do not drive constantly at full-throttle or high engine rpm for extended periods of time. Avoid unnecessary hard stops. Avoid full-throttle starts.

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