Lexus RX300 (MCU15). Manual - part 261

DI–276

–

DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

LEXUS RX300   (RM785E)

4

Check for open circuit in harness and connector between skid control ECU and
stop light switch (See page IN–32).

NG

Repair or replace harness or connector.

OK

Proceed to next circuit inspection on prob-
lem symptoms table (See page DI–220).

F05279

Battery

Fusible Link
Block
ABS

R/B No. 2

ABS 
SOL Relay

ABS Motor Relay

Brake Actuator

2

3

W

B

2

2

2

2

2

1

5

3

2

3

W–L

W–B

A7

W–B

W–B

LG–B

B–W

GR

29

A21

MR

MT

Skid Control ECU

EA

ED

1

A21

R+

A21

28

A7

A7

1

–

DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

DI–277

LEXUS RX300   (RM785E)

DTC

C1251 / 51

ABS Pump Motor Lock

CIRCUIT DESCRIPTION

DTC No.

DTC Detecting Condition

Trouble Area

C1251 / 51

Either of the following 1. or 2. is detected:

1. Brake actuator pump motor is not operating normally.

2. Open circuit condition of brake actuator pump motor

continues for 2 sec. or more.

ABS pump motor

WIRING DIAGRAM

DI84R–01

F03648

(+)

(–)

BM

GND

DI–278

–

DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

LEXUS RX300   (RM785E)

INSPECTION PROCEDURE

1

Check operation of pump motor.

PREPARATION:
Disconnect the connector from the brake actuator.
CHECK:
Connect positive ę lead to BM terminal and negative Ĝ lead
to GND terminal of the brake actuator, check that the pump mo-
tor is operated.
OK:

The running sound of the pump motor should be
heard.

OK

Check for open circuit in harness and connec-
tor between ABS motor relay, brake actuator
and ECU (See page IN–32).

NG

Replace brake actuator.

F13431

14

SS1–

Skid Control ECU

Steering Angle Sensor

LG–B

A23

LG

SS1+

23

A23

SS1–

SS1+

3

6

–

DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

DI–279

LEXUS RX300   (RM785E)

DTC

C1335 / 35

Steering Angle Sensor Communication
Circuit Malfunction

CIRCUIT DESCRIPTION

DTC No.

DTC Detecting Condition

Trouble Area

C1335 / 35

When the condition that ECU terminal IG1 voltage is  9.5 V

or more, and ECU does not receive data from steering

angle sensor continues for 1 sec. or more.

Steering angle sensor circuit

WIRING DIAGRAM

DI84S–01