Lexus RX (RX 350L, RX450h) 2016-2024 Repair Manual: Terminals Of Ecu

TERMINALS OF ECU

CHECK ECM

HINT:

As a waterproof connector is used for the ECM, voltage, resistance and waveform inspections cannot be performed. The voltage, resistance and waveform values are provided for reference only.

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

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

A37-27 (STP) - D2-53 (E1)

Y - BR

Stop light switch assembly signal

Brake pedal depressed

11 to 14 V

Brake pedal released

Below 1 V

A37-41 (CCS) - D2-53 (E1)

B - BR

Cruise control main switch circuit

Cruise control main switch (ON/OFF button) not pushed

1 MΩ or higher

Cruise control main switch (ON/OFF button) pushed

Below 2.5 Ω

+RES switch ON

235 to 245 Ω

-SET switch ON

617 to 643 Ω

CANCEL switch ON

1509 to 1571 Ω

A37-42 (ST1-) - D2-53 (E1)

BR - BR

Stop light switch assembly signal

Engine switch on (IG), brake pedal depressed

Below 1 V

Engine switch on (IG), brake pedal released

11 to 14 V

CHECK FORWARD RECOGNITION CAMERA

NOTICE:

  • DTCs may be output when connectors are disconnected during inspection. Therefore, be sure to clear the DTCs using the Techstream once the inspection has been completed.
  • Do not apply excessive force to the forward recognition camera connector.

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

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

U14-3 (LKSW) - U14-10 (GND)

GR - BR

Steering pad switch assembly signal (distance control signal)

Engine switch on (IG), steering pad switch assembly (vehicle-to-vehicle distance control switch) on

Below 1 V

Engine switch on (IG), steering pad switch assembly (vehicle-to-vehicle distance control switch) off

4.75 to 5.25 V

U14-7 (IGB) - U14-10 (GND)

SB - BR

Power source

Engine switch on (IG)

11 to 14 V

Engine switch off

Below 1 V

U14-8 (BZ) - U14-10 (GND)

W - BR

Skid control buzzer assembly output

Engine switch on (IG), buzzer not sounding

11 to 14 V

Engine switch on (IG), buzzer sounding

Below 1 V

U14-10 (GND) - Body ground

BR - Body ground

Ground

Always

Below 1 Ω

(b) Check for pulses according to the value(s) in the table below.

HINT:

If the waveform is not similar to that shown in the illustration, a malfunction of a CAN bus line, terminating resistor, or the forward recognition camera is suspected.

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

U14-5 (CA1P) - U14-10 (GND)

V - BR

CAN communication signal

Engine switch on (IG)

Pulse generation

(See waveform 1)

U14-6 (CANH) - U14-10 (GND)

B - BR

CAN communication signal

Engine switch on (IG)

Pulse generation

(See waveform 1)

U14-11 (CA1N) - U14-10 (GND)

P - BR

CAN communication signal

Engine switch on (IG)

Pulse generation

(See waveform 2)

U14-12 (CANL) - U14-10 (GND)

W - BR

CAN communication signal

Engine switch on (IG)

Pulse generation

(See waveform 2)

(1) Waveform 1

Item

Content

Tester Connection

  • Between U14-5 (CA1P) and U14-10 (GND)
  • Between U14-6 (CANH) and U14-10 (GND)

Tool Setting

1 V/DIV., 10 μs./DIV.

Condition

Engine switch on (IG)

HINT:

The waveform varies depending on the CAN communication signal.

(2) Waveform 2

Item

Content

Tester Connection

  • Between U14-11 (CA1N) and U14-10 (GND)
  • Between U14-12 (CANL) and U14-10 (GND)

Tool Setting

1 V/DIV., 10 μs./DIV.

Condition

Engine switch on (IG)

HINT:

The waveform varies depending on the CAN communication signal.

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