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

A74-20 (STA) - Body ground

Input

B - Body ground

When starting the engine, this monitors the voltage sent from terminal STAR to the starter relay to judge whether the engine is "being started".

20°C (68°F)

106.78 to 115.98 Ω

-

A74-9 (STAR) - Body ground

Input/Output

B - Body ground

Outputs voltage to the starter relay

HINT:

When Hi is selected, a start request signal (STAR) will not be output even though a start request signal (STSW) is input.

Shift lever in any position other than P or N → Shift lever in P or N (at 20°C (68°F))

10 kΩ or higher → 107.05 to 116.33 Ω

-

Receives neutral start switch (P, N position detection) signal

Perform the following operations except while the engine is cranking:

30 kΩ or higher → 107.05 to 116.33 Ω

Neutral SW/ Clutch SW

A74-16 (NE) - Body ground

Input

B - Body ground

Engine speed signal

Always

10 kΩ or higher

Engine Condition

R1-25 (STP1) - Body ground

Input

B - Body ground

Stop light switch signal

Brake pedal depressed → Brake pedal released

9 V or higher → 1 V or less

Stop Light Switch1

J41-4 (+B) - J41-18 (E)

Input

V - W-B

Power source

Always

11 to 14 V

-

J41-22 (P) - J41-18 (E)

Input

SB - W-B

P position signal

Shift lever in P → Shift lever not in P

30 kΩ or higher → Below 200 Ω

Shift P Signal

J41-18 (E) - Body ground

-

W-B - Body ground

GND

Always

Below 1 Ω

-

J41-21 (SSW2) - Body ground

Input

V - Body ground

SSW2 contact signal

HINT:

Backup for SSW1. Behaves the same way as SSW1.

Engine switch pushed → Engine switch not pushed

Below 15 Ω → 10 kΩ or higher

Start Switch2

J41-23 (SSW1) - Body ground

Input

P - Body ground

SSW1 contact signal

Engine switch pushed → Engine switch not pushed

Below 15 Ω → 10 kΩ or higher

Start Switch1

J41-16 (ACCD) - Body ground

Output

Y - Body ground

ACC signal

20°C (68°F)

285.71 to 428.57 Ω

ACC Relay Monitor

J41-17 (IG1D) - Body ground

Output

G - Body ground

IG signal

20°C (68°F)

55.04 to 88.24 Ω

IG Relay Monitor (Outside)

J41-19 (SPD) - Body ground

Input

SB - Body ground

Vehicle speed signal

Always

30 kΩ or higher

Vehicle Speed Signal

A74-20 (STA) - J41-18 (E)

Input

B - W-B

When starting the engine, this monitors the voltage sent from terminal STAR to the starter relay to judge whether the engine is "being started".

Engine switch pressed and held with brake pedal depressed (starter on) → Approximately 1 second after engine switch released (starter off)

6 V or higher* → 1.0 V or less

-

A74-9 (STAR) - J41-18 (E)

Input/Output

B - W-B

Outputs voltage to the starter relay

HINT:

When Hi is selected, a start request signal (STAR) will not be output even though a start request signal (STSW) is input.

Engine switch pressed and held with brake pedal depressed (starter on) → Approximately 1 second after engine switch released (starter off)

6 V or higher* → 1.0 V or less

-

Receives neutral start switch (P, N position detection) signal

Perform the following operations except while the engine is cranking:

9 V or higher → 2.7 V or less

Neutral SW/ Clutch SW

A74-16 (NE) - J41-18 (E)

Input

B - W-B

Engine speed signal

Idling (engine warmed up)

Pulse generation

(See waveform 1)

Engine Condition

R1-25 (STP1) - J41-18 (E)

Input

B - W-B

Stop light switch signal

Brake pedal released → Brake pedal depressed

1 V or less → 9 V or higher

Stop Light Switch1

J41-14 (SLP) - J41-18 (E)

Input

P - W-B

Steering lock position signal

Steering locked → Steering unlocked

11 to 14 V → 1.5 V or less

Steering Unlock Switch

J41-25 (SLR+) - J41-18 (E)

Output

SB - W-B

Steering lock motor operation command signal

(Steering lock motor operation permission signal sent from the certification ECU (smart key ECU assembly))

When a door is opened, the steering lock motor will be operated if all of the following conditions are met:

Pulse generation

(See waveform 2)

-

J41-22 (P) - J41-18 (E)

Input

SB - W-B

P position signal

Shift lever in P → Shift lever not in P

9 V or higher → 2.76 V or less

Shift P Signal

J41-21 (SSW2) - J41-18 (E)

Input

V - W-B

SSW2 contact signal

HINT:

Backup for SSW1. Behaves the same way as SSW1.

Engine switch not pushed → Engine switch pushed

9 V or higher → 1 V or less

Start Switch2

J41-23 (SSW1) - J41-18 (E)

Input

P - W-B

SSW1 contact signal

Engine switch not pushed → Engine switch pushed

9 V or higher → 1 V or less

Start Switch1

J41-16 (ACCD) - J41-18 (E)

Output

Y - W-B

ACC signal

Engine switch off → Engine switch on (ACC)

1 V or less → 8.5 V or higher

ACC Relay Monitor

J41-17 (IG1D) - J41-18 (E)

Output

G - W-B

IG signal

Engine switch on (ACC) → Engine switch on (IG)

1 V or less → 9 V or higher

IG Relay Monitor (Outside)

J41-19 (SPD) - J41-18 (E)

Input

SB - W-B

Vehicle speed signal

Vehicle being driven at approx. 5 km/h (3 mph)

Pulse generation

(See waveform 3)

Vehicle Speed Signal

J41-8 (CLG5) - J41-18 (E)

Output

B - W-B

Output to No. 1 indoor electrical key antenna assembly (front floor)

Procedure:

Pulse generation

(See waveform 4)

Overhead + Front Room (key diagnostic mode)

J41-9 (CG5B) - J41-18 (E)

Output

Y - W-B

Output to No. 1 indoor electrical key antenna assembly (front floor) (terminal on opposite side of component from CLG5 output terminal)

Procedure:

Pulse generation

(See waveform 4)

Overhead + Front Room (key diagnostic mode)

R1-5 (CLG6) - J41-18 (E)

Output

P - W-B

Output to No. 2 indoor electrical key antenna assembly (rear floor)

Procedure:

Pulse generation

(See waveform 4)

Overhead + Rear Room (key diagnostic mode)

R1-6 (CG6B) - J41-18 (E)

Output

L - W-B

Output to No. 2 indoor electrical key antenna assembly (rear floor) (terminal on opposite side of component from CLG6 output terminal)

Procedure:

Pulse generation

(See waveform 4)

Overhead + Rear Room (key diagnostic mode)

R1-11 (CLG7) - J41-18 (E)

Output

V - W-B

Output to No. 3 indoor electrical key antenna assembly (inside luggage compartment)

Procedure:

Pulse generation

(See waveform 4)

Overhead + Back Door (inside) (key diagnostic mode)

R1-10 (CG7B) - J41-18 (E)

Output

W - W-B

Output to No. 3 indoor electrical key antenna assembly (inside luggage compartment) (terminal on opposite side of component from CLG7 output terminal)

Procedure:

Pulse generation

(See waveform 4)

Overhead + Back Door (inside) (key diagnostic mode)

Tester Connection

A74-16 (NE) - J41-18 (E)

Tool Setting

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

Condition

Idling (engine warmed up)

*a

Steering lock motor not operating

*b

Steering lock motor operating

Tester Connection

J41-25 (SLR+) - J41-18(E)

Tool Setting

2 V/DIV., 200 ms./DIV.

Condition

Steering lock motor stopped → Steering lock motor operating → Steering lock motor stopped

Tester Connection

J41-19 (SPD) - J41-18(E)

Tool Setting

5 V/DIV., 20 ms./DIV.

Condition

Vehicle being driven at approx. 5 km/h (3 mph)

*a

For 30 seconds after any door closed

*b

After 30 seconds or more have elapsed since any door closed

Tester Connection

J41-8 (CLG5) - J41-18 (E)

J41-9 (CG5B) - J41-18 (E)

R1-5 (CLG6) - J41-18 (E)

R1-6 (CG6B) - J41-18 (E)

R1-11 (CLG7) - J41-18 (E)

R1-10 (CG7B) - J41-18 (E)

Tool Setting

2 V/DIV., 500 ms/DIV.

Condition

Procedure: