Lexus RX300 (MCU15). Service manual - part 246

DI0WC–09

F12362

SLIP Indicator Light
ABS Warning Light 
VSC Warning Light 
Brake Warning Light*

Front Sensor Rotor

Skid Control ECU

Level Warning Switch

Sensor Rotor

Rear Speed Sensor

Front Speed Sensor

Brake Actuator

Yaw Rate Sensor

ABS Motor Relay

ABS SOL Relay

Steering Angle Sensor

Deceleration Sensor

Stop Light Switch

DLC3

Parking Brake Switch

*: w/ EBD only

R/B No. 2

VSC Buzzer

DI–216

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DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

LEXUS RX300   (RM785E)

PARTS LOCATION

DI84N–01

F02094

A20

A23

A22

A21

–

DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

DI–217

LEXUS RX300   (RM785E)

TERMINALS OF ECU

Symbols (Terminals No.)

Wiring Color

Condition

STD Voltage (V)

SRLR (A20 – 1) – GND (A21 –

6, 31, A22 – 8, 17)

B–O ↔ W–B

IG switch ON, ABS warning light OFF

10 – 14

AST (A20 – 6) – GND (A21 – 6,

31, A22 – 8, 17)

B–Y ↔ W–B

IG switch ON, ABS warning light OFF

10 – 14

SRLH (A20 – 7) – GND (A21 –

6, 31, A22 – 8, 17)

Y–B ↔ W–B

IG switch ON, ABS warning light OFF

10 – 14

SFRR (A20 – 8) – GND (A21 –

6, 31, A22 – 8, 17)

BR–W ↔ W–B

IG switch ON, ABS warning light OFF

10 – 14

SMV2 (A20 – 15) – GND (A21

– 6, 31, A22 – 8, 17)

R ↔ W–B

IG switch ON, ABS warning light OFF

10 – 14

SFRH (A20 – 16) – GND (A21

– 6, 31, A22 – 8, 17)

V–W ↔ W–B

IG switch ON, ABS warning light OFF

10 – 14

SMV1 (A20 – 22) – GND (A21

– 6, 31, A22 – 8, 17)

W–L ↔ W–B

IG switch ON, ABS warning light OFF

10 – 14

SMC1 (A21 – 2) – GND (A21 –

6, 31, A22 – 8, 17)

L–Y ↔ W–B

IG switch ON, ABS warning light OFF

10 – 14

SMC2 (A21 – 3) – GND (A21 –

6, 31, A22 – 8, 17)

G–B ↔ W–B

IG switch ON, ABS warning light OFF

10 – 14

SRC1 (A21 – 4) – GND (A21 –

6, 31, A22 – 8, 17)

R–Y ↔ W–B

IG switch ON, ABS warning light OFF

10 – 14

SRC2 (A21 – 5) – GND (A21 –

6, 31, A22 – 8, 17)

GR–R ↔ W–B

IG switch ON, ABS warning light OFF

10 – 14

SFLR (A21 – 7) – GND (A21 –

6, 31, A22 – 8, 17)

R–B ↔ W–B

IG switch ON, ABS warning light OFF

10 – 14

SRRH (A21 – 8) – GND (A21 –

6, 31, A22 – 8, 17)

BR–Y ↔ W–B

IG switch ON, ABS warning light OFF

10 – 14

SRRR (A21 – 9) – GND (A21 –

6, 31, A22 – 8, 17)

GR–L ↔ W–B

IG switch ON, ABS warning light OFF

10 – 14

VCM (A21 – 10) – GND (A21 –

6, 31, A22 – 8, 17)

B ↔ W–B

IG switch ON

4.5 – 5.5

FR+ (A21 – 14) – FR– (A21 –

13)

V ↔ P

IG switch ON, slowly turn right front wheel

AC generation

FL+ (A21 – 16) – FL– (A21 –

15)

LG ↔ L

IG switch ON, slowly turn left front wheel

AC generation

SR (A21 – 19) – R+ (A21 – 1)

Y–G ↔ GR

IG switch ON, ABS warning light OFF

10 – 14

SFLH (A21 – 21) – GND (A21 –

6, 31, A22 – 8, 17)

G ↔ W–B

IG switch ON, ABS warning light OFF

10 – 14

DI–218

–

DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

LEXUS RX300   (RM785E)

PMC (A21 – 22) – E2 (A21 –

23)

W ↔ R

IG switch ON, stop light switch OFF

0.3 – 0.7

E2 (A21 – 23) – GND (A21 – 6,

31, A22 – 8, 17)

R ↔ W–B

IG switch OFF

Continuity

FSS (A21 – 24) – GND (A21 –

6, 31, A22 – 8, 17)

Shielded ↔ W–B

IG switch OFF

Continuity

MT (A21 – 28) – GND (A21 – 6,

31, A22 – 8, 17)

LG–B ↔ W–B

IG switch ON (Motor relay is OFF)

Below 1.5

MR (A21 – 29) – GND (A21 – 6,

31, A22 – 8, 17)

B–W ↔ W–B

IG switch ON, ABS motor stops

10 – 14

VGS (A22 – 1) – GGND (A22 –

10)

R ↔ B

IG switch ON

4.5 – 5.5

GL1 (A22 – 2) – GGND (A22 –

10)

W ↔ B

IG switch ON, vehicle is placed on the horizontal surface

2 – 3

Tc (A22 – 3) – GND (A21 – 6,

31, A22 – 8, 17)

P–B ↔ W–B

IG switch ON

10 – 14

Ts (A22 – 4) – GND (A21 – 6,

31, A22 – 8, 17)

W–L ↔ W–B

IG switch ON

10 – 14

IG1 (A22 – 6) – GND (A21 – 6,

31, A22 – 8, 17)

B–R ↔ W–B

IG switch ON

10 – 14

NEO (A22 – 7) – GND (A21 –

6, 31, A22 – 8, 17)

L–O ↔ W–B

Engine idling

Pulse generation

GL2 (A22 – 9) – GGND (A22 –

10)

G ↔ B

IG switch ON,  vehicle is placed on the level surface

2.0 – 3.0

GGND (A22 – 10) – GND (A21

– 6, 31, A22 – 8, 17)

B ↔ W–B

IG switch OFF

Continuity

RR+ (A22 – 11) – RR– (A22 –

12)

GR–R ↔ L

IG switch ON, slowly turn right rear wheel

AC generation

ENG+ (A22 – 14) – ENG– (A22

– 22)

R–Y ↔ BR–W

IG switch ON, engine idling

Pulse generation

GSS (A22 – 18) – GND (A21 –

6, 31, A22 – 8, 17)

Shielded ↔ W–B

IG switch OFF

Continuity

RL+ (A22 – 19) – RL– (A22 –

20)

L–Y ↔ L–W

IG switch ON, slowly turn left rear wheel

AC generation

PKB (A22–15) – GND (A21–6,

R L ↔ W B

IG switch ON, parking brake switch ON

Below 2.0

PKB (A22 15)   GND (A21 6,

31, A22 – 8, 17)

R–L ↔ W–B

IG switch ON, parking brake switch OFF

10 – 14

TRC+ (A22 – 24) – TRC– (A22

– 16)

GR ↔ P–B

IG switch ON, engine idling

Pulse generation

BRL (A23 – 1) – GND (A21 – 6,

31, A22 – 8, 17)

G ↔ W–B

IG switch ON, fluid in master cylinder reservoir above MIN level

and parking brake switch is OFF (Brake warning light is OFF)

10 – 14

VSCW (A23 – 4) – GND (A21 –

W G ↔ W B

IG switch ON, VSC warning light ON

Below 2.0

VSCW (A23   4)   GND (A21 

6, 31, A22 – 8, 17)

W–G ↔ W–B

IG switch ON, VSC warning light OFF

10 – 14

WA (A23 – 5) – GND (A21 – 6,

B Y ↔ W B

IG switch ON, ABS warning light ON

Below 2.0

WA (A23   5)   GND (A21   6,

31, A22 – 8, 17)

B–Y ↔ W–B

IG switch ON, ABS warning light OFF

10 – 14

IND (A23 – 6) – GND (A21 – 6,

W L ↔ W B

IG switch ON, SLIP indicator light ON

Below 2.0

IND (A23   6)   GND (A21   6,

31, A22 – 8, 17)

W–L ↔ W–B

IG switch ON, SLIP indicator light OFF

10 – 14

STP (A23 – 7) – GND (A21 – 6,

G Y ↔ W B

Stop light switch OFF

Below 1.5

STP (A23   7)   GND (A21   6,

31, A22 – 8, 17)

G–Y ↔ W–B

Stop light switch ON

8 – 14

VYS (A23 – 9) – GYAW (A23 –

27)

R–L ↔ R–W

IG switch ON

4.5 – 5.5

–

DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

DI–219

LEXUS RX300   (RM785E)

LBL (A23 – 11) – GND (A21 –

6, 31, A22 – 8, 17)

R–W ↔ W–B

IG switch ON, fluid in master cylinder reservoir above MIN level

About 4 – 8

SS1+ (A23 – 14) – SS1– (A23 –

23)

LG–B ↔ LG

Engine idling, slowly turn steering wheel

Pulse generation

(See page DI–255)

R (A23 – 15) – GND (A21 – 6,

R B

W B

IG switch ON, sift lever is in R range

8 – 14

R (A23   15)   GND (A21   6,

31, A22 – 8, 17)

R–B ↔ W–B

IG switch ON, sift lever is in other than R range

Below 1.5

SP1 (A23 – 16) – GND (A21 –

6, 31, A22 – 8, 17)

R–B ↔ W–B

Vehicle driving at about 20 km/h (12 mph)

Pulse generation

YSS (A23 – 18) – GND (A21 –

6, 31, A22 – 8, 17)

Shielded ↔ W–B

IG switch OFF

Continuity

YD (A23 – 19) – GND (A21 – 6,

31, A22 – 8, 17)

W–R ↔ W–B

IG switch ON, VSC warning light OFF

4.5 – 5.5

BZ (A23 – 20) – GND (A21 – 6,

G O ↔ W B

IG switch ON, VSC buzzer sounds

Below 1.0 ↔ 10 – 14

BZ (A23   20)   GND (A21   6,

31, A22 – 8, 17)

G–O ↔ W–B

IG switch ON, VSC buzzer does not sound

10 – 14

D (A23 – 22) – GND (A21–6,

G R ↔ W B

IG switch ON, shift lever is in D range

8 – 14

D (A23   22)   GND (A21 6,

31, A22 – 8, 17)

G–R ↔ W–B

IG switch ON, shift lever is in other than D range

Below 1.5

P (A23 – 24) – GND (A21 – 6,

G W ↔ W B

IG switch ON, sift lever is in P range

8 – 14

P (A23   24)   GND (A21   6,

31, A22 – 8, 17)

G–W ↔ W–B

IG switch ON, sift lever is in other than P range

Below 1.5

D/G (A23 – 25) – GND (A21 –

6, 31, A22 – 8, 17)

W ↔ W–B

IG switch ON

10 – 14

GYAW (A23 – 27) – GND (A21

– 6, 31, A22 – 8, 17)

R–W ↔ W–B

IG switch OFF

Continuity

YAW (A23 – 28) – GYAW (A23

– 27)

B ↔ R–W

IG switch ON, vehicle is in stationary condition

2 – 3