Lexus RX300 (MCU15). Service manual — part 257

F09210

Yaw Rate Sensor

YD

GYAW

YAW2

VYS

3

1

5

4

(Shielded)

R–W

B

R–L

W–R

5

17

16

15

9

IM1

(Shielded)

Skid Control ECU

18

27

28

9

19

A23 YSS

YD

GYAW

YAW

VYS

IM1

IM1

IM1

IM1

R–W

B

R–L

W–R

A23

A23

A23

A23

DI–260

–

DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

LEXUS RX300 (RM785E)

DTC

C1233 / 33, C1234 / 34

Yaw Rate Sensor Circuit

CIRCUIT DESCRIPTION

DTC No.

DTC Detecting Condition

Trouble Area

C1233 / 33

When any of the following 1. through 4. is detected:

1. ECU terminal IG1 voltage is 9.5 to 17.2 V and the yaw

rate sensor voltage is continuously out of the range from

0.25 to 4.75 V for 1 sec. or more.

2. ECU terminal IG1 voltage is 9.5 to 17.2 V and the yaw

rate sensor open circuit detection signal remains ON for

1 sec. or more.

3. ECU terminal IG1 voltage is 9.5 to 17.2 V and the yaw

rate sensor power source voltage remains out of the

range from 4.4 to 5.6 V for 1 sec. or more.

4. Momentary interruption of the yaw rate sensor signal

occurs 10 times or more.

S Yaw rate sensor

S Yaw rate sensor circuit

C1234 / 34

When the condition that yaw rate sensor voltage is 4.4 V to

5.6 V and YD malfunction signal of yaw rate sensor is ON

continued for 5 sec. or more.

WIRING DIAGRAM

DI6GH–03

F02808

–

DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

DI–261

LEXUS RX300 (RM785E)

INSPECTION PROCEDURE

1

Perform zero point calibration of the yaw rate sensor (See page DI–205).

2

Is DTC still output?

Check DTC on page DI–205.

NO No

problem.

YES

3

Check output value of the yaw rate sensor.

In case of using the hand–held tester:
PREPARATION:
(a)

Remove the 2 bolts and yaw rate sensor with connector
still connected.

(b)

Connect the hand–held tester to the DLC3.

(c)

Turn the ignition switch ON and push the hand–held tes-
ter main switch ON.

(d)

Select the DATALIST mode on the hand–held tester.

CHECK:
Check that the yaw rate value of the yaw rate sensor displayed
on the hand–held tester is changing: Place the yaw rate sensor
vertically to the ground and turn the sensor pivoted on its center.
OK:

Yaw rate value must be changing.

F02123

1

4

3

(+)

(–)

(–)

(+)

F02864

GND

YD

(–)

(+)

ON

DI–262

–

DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

LEXUS RX300 (RM785E)

In case of not using the hand–held tester:
PREPARATION:
(a)

Turn the ignition switch ON.

(b)

Measure voltage between terminals 1 and 3, 3 and 4 of
the yaw rate sensor with connector still connector.

OK:

Terminals 1 and 3

(YAW – GYAW)

APPROX. 2.5 V

Terminals 3 and 4

(GYAW – YD)

APPROX. 4.5 V – 5.5 V

NG

Replace yaw rate sensor.

OK

4

Check voltage between terminals YD and GND of skid control ECU.

PREPARATION:
Remove the skid control ECU withe connector still connected.
CHECK:
(a)

Turn the ignition switch ON.

(b)

Measure voltage between terminals YD and GND of skid
control ECU.

OK:

Voltage: 4.5 – 5.3 V

OK

Check and replace skid control ECU.

NG

5

Check for open and short circuit in harness and connector between yaw rate
sensor and skid control ECU (See page IN–32).

NG

Repair or replace harness or connector.

OK

Check and replace skid control ECU.

F13429

Ignition Switch

Instrument Panel J/B

Skid Control ECU

Battery

W

4

2

B–Y

B–R

W–L

W–B

W–B

1C

II1

6

1

6

IG1

GND4

GND3

GND1

ECU–IG

AM1

W

J9
Junnction
Connector

W–B

GND2

1A

5E

11

1

8

17

W–B

W–B

Instrument Panel J/B

A22

31

1

2

7

1C

10

1D

A22

A22

A21

6

A21

IG

IF

A

7

5D

Fusible Link
Block
ALT

J/B No.5

W–B

W–B

5

3

–

DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

DI–263

LEXUS RX300 (RM785E)

DTC

C1241 / 41

IG Power Source Circuit

CIRCUIT DESCRIPTION

DTC No.

DTC Detecting Condition

Trouble Area

C1241 / 41

Detection of any of conditions 1. or 2.:

1. Vehicle speed is 3 km/h (1.9 mph) or more and voltage

of ECU terminal IG remains at below 9.5 V for more than

10 sec.

2. While the condition that the solenoid relay is ON contin-

ues, ECU terminal IG1 voltage becomes 9.5 V or less,

and the condition that the contact point of the solenoid

relay is OFF continues for 0.2 sec. or more.

S Battery

S Charging system

S Power source circuit

WIRING DIAGRAM

DI0WV–14