Toyota Camry owners & service manuals

Toyota Camry (XV70): Terminals Of Ecu

TERMINALS OF ECU

CHECK TIRE PRESSURE WARNING ECU AND RECEIVER

(a) Disconnect the R127 or R128 tire pressure warning ECU and receiver connector and measure the voltage or resistance on the wire harness side.

*A

w/ Smart Key System

*B

w/o Smart Key System

*a

Front view of wire harness connector

(to Tire Pressure Warning ECU and Receiver)

w/ Smart Key System

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

R127-1 (IG) - R127-12 (GND)

LA-B - W-B

IG power source

Ignition switch ON

10 to 16 V

R127-7 (+B) - R127-12 (GND)

LA-R - W-B

Power supply (from battery)

Always

10 to 16 V

R127-9 (CANH) - R127-10 (CANL)*

L - W

CAN communication line

Ignition switch off

54 to 69 Ω

R127-12 (GND) - Body ground

W-B - Body ground

Ground

Always

Below 1 Ω

  • *: w/ Tire Inflation Pressure Display Function
w/o Smart Key System

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

R128-1 (IG) - R128-12 (GND)

LA-LG - W-B*2

LA-B - W-B*3

IG power source

Ignition switch ON

10 to 16 V

R128-7 (+B) - R128-12 (GND)

LA-L - W-B

Power supply (from battery)

Always

10 to 16 V

R128-9 (CANH) - R128-10 (CANL)*1

L - W

CAN communication line

Ignition switch off

54 to 69 Ω

R128-12 (GND) - Body ground

W-B - Body ground

Ground

Always

Below 1 Ω

  • *1: w/ Tire Inflation Pressure Display Function
  • *2: w/ Blind Spot Monitor System
  • *3: w/o Blind Spot Monitor System

(b) Connect the R127 or R128 tire pressure warning ECU and receiver connector.

(c) Measure the voltage according to the value(s) in the table below. If the result is not as specified, the ECU may be malfunctioning.

HINT:

Measure the values on the wire harness side while the connector is connected.

*A

w/ Smart Key System

*B

w/o Smart Key System

*a

Component with harness connected

(Tire Pressure Warning ECU and Receiver)

-

-

w/ Smart Key System

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

R127-3 (CLSW) - R127-12 (GND)

SB - W-B

Tire pressure warning reset switch

  • Ignition switch ON
  • Steering pad switch assembly operated, "Set Pressure" selected on the multi-information display and "OK" switch (steering pad switch assembly) pressed and held

Below 1.5 V

  • Ignition switch ON
  • "OK" switch (steering pad switch assembly) off

8 to 15 V

R127-4 (RDA) - R127-12 (GND)

GR - W-B

Output signals

Ignition switch ON

Pulse generation (see waveform 1)

R127-5 (PRG) - R127-12 (GND)

R - W-B

Input signals

Ignition switch ON

Pulse generation (see waveform 1)

w/o Smart Key System

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

R128-3 (CLSW) - R128-12 (GND)

SB - W-B

Tire pressure warning reset switch

  • Ignition switch ON
  • Steering pad switch assembly operated, "Set Pressure" selected on the multi-information display and "OK" switch (steering pad switch assembly) pressed and held

Below 1.5 V

  • Ignition switch ON
  • "OK" switch (steering pad switch assembly) off

8 to 15 V

R128-4 (RDA) - R128-12 (GND)

GR - W-B

Output signals

Ignition switch ON

Pulse generation (see waveform 1)

R128-5 (PRG) - R128-12 (GND)

R - W-B

Input signals

Ignition switch ON

Pulse generation (see waveform 1)

(d) Using an oscilloscope, check waveform 1.

*a

Example

*b

GND

Waveform 1:

Item

Contents

Terminal

R127-4 (RDA) - R127-12 (GND)*1

R128-4 (RDA) - R128-12 (GND)*2

R127-5 (PRG) - R127-12 (GND)*1

R128-5 (PRG) - R128-12 (GND)*2

Tool setting

5 V/DIV, 5 ms./DIV.

Vehicle condition

Ignition switch ON

  • *1: w/ Smart Key System
  • *2: w/o Smart Key System

HINT:

The waveform shown in the illustration is an example. If the tester displays a waveform that alternates between high and low, where high is a voltage that is between the IG power source voltage and a voltage 2.2 V lower than the IG power source voltage, and where low is a voltage of between 0 and 1.2 V, the ECU can be judged normal.

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