Lexus RX300 (MCU15). Service manual - part 244

BR3893

Malfunction Code (Example Code 72, 76)

7

2

6

7

ON

OFF

0.5 sec.

0.5 sec.

0.5 sec.

0.5 sec.

1.5 sec.

2.5 sec.

4 sec.

Repeat

D09456

Hand–held Tester

DLC3

DI–208

–

DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

LEXUS RX300   (RM785E)

HINT:

S

See the list of DTC shown in the next page.

S

If every sensor is normal, a normal code is output (A cycle
of 0.25 sec. ON and 0.25 sec. OFF is repeated).

S

If 2 or more malfunctions are indicated at the same time,
the lowest numbered code will be displayed 1st.

(12) After doing the check, disconnect terminals Ts and

CG, Tc and CG of DLC3, and turn the ignition switch
OFF.

SST

09843–18040

(b)

In case of using hand–held tester:
Check the ABS sensor signal.
(1)

Hook up the hand–held tester to the DLC3.

(2)

Do step (3) to (9) on the previous page.

(3)

Read the DTC by following the prompts on the tes-
ter screen.

HINT:
Please refer to the hand–held tester operator’s manual for fur-
ther details.

F09750

Tc

DLC3

CG

Ts

BR3904

0.13 sec.

0.13 sec.

ON

OFF

–

DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

DI–209

LEXUS RX300   (RM785E)

DTC of ABS sensor check function:

Code No.

Diagnosis

Trouble Area

C1271 / 71

Low output voltage of right front speed sensor

S Right front speed sensor

S Sensor installation

S Sensor rotor

C1272 / 72

Low output voltage of left front speed sensor

S Left front speed sensor

S Sensor installation

S Sensor rotor

C1273 / 73

Low output voltage of right rear speed sensor

S Right rear speed sensor

S Sensor installation

S Sensor rotor

C1274 / 74

Low output voltage of left rear speed sensor

S Left rear speed sensor

S Sensor installation

S Sensor rotor

C1275 / 75

Abnormal change in output voltage of right front speed sen-

sor

Right front speed sensor rotor

C1276 / 76

Abnormal change in output voltage of left front speed sen-

sor

Left front speed sensor rotor

C1277 / 77

Abnormal change in output voltage of right rear speed sen-

sor

Right rear speed sensor rotor

C1278 / 78

Abnormal change in output voltage of left rear speed sensor

Left rear speed sensor rotor

C1279 / 79

Deceleration sensor is faulty

S Deceleration sensor

S Sensor installation

C1281 / 81

Master cylinder pressure sensor output signal is faulty

Master cylinder pressure sensor

(c)

In case of not using hand–held tester:
Check the VSC sensor signal.
(1)

Turn the ignition switch OFF.

(2)

Check that the shift lever position is at P range, turn
the steering wheel to the neutral position.

(3)

Using SST, connect terminals Ts and CG of DLC3.

SST

09843–18040

(4)

Start the engine.

(5)

Check that the VSC warning light blinks.

HINT:
If the VSC warning light does not blink, inspect the VSC warning
light circuit and Ts terminal circuit (See page DI–284, 
DI–300).

(6)

After a new ECU installed, the first time only:
Start the engine and keep the vehicle in the station-
ary condition on the flat place for 3 sec. or more, it’s
installed the zero point calibration of the yaw rate
sensor.

F02135

Start Position

End Position

Within ± 5°

Malfunction Code (Example Code 71, 72)

ON

OFF

0.5 sec.

0.5 sec.

1.5 sec.

2.5 sec.

4 sec.

Repeat

71

72

DI–210

–

DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

LEXUS RX300   (RM785E)

(7)

Check the steering angle sensor.
Turn the steering wheel to either left or right to the
full lock position, from the vehicle stationary condi-
tion, and turn back the steering wheel to the neutral
position.

(8)

Check the yaw rate sensor.
Shift the shift lever to the D range and drive the ve-
hicle at the vehicle speed of approx. 5 km/h (3 mph),
turn the steering wheel either to left or right 90° or
more, and maintain 180° circular drive for the ve-
hicle.
Stop the vehicle and shift the shift lever to the P
range, check that the VSC buzzer sounds for 3 sec.

HINT:

S

If the VSC buzzer sounds, the sensor check is in normal
completion.

S

If the VSC buzzer does not sound, check the VSC buzzer
circuit (See page DI–295), then do the sensor check
again.

S

If the VSC buzzer still won’t sound, there is a malfunction
in the VSC sensor, so check the DTC.

S

Drive the vehicle in a 180° circle. At the end of the turn,
the direction of the vehicle should be within 180°±5° of
its start position.

S

Do not spin the wheels.
(9)

Using SST, connect terminals Tc and CG of DLC3.

SST

09843–18040

(10) Read the number of blinks of the VSC warning light.

HINT:

S

See the list of DTC shown at in the next page.

S

If every sensor is normal, a normal code is output. (A cycle
of 0.25 sec. ON and 0.25 sec. OFF is repeated.)

S

If 2 or more malfunctions are indicated at the same time,
the lowest numbered code will be displayed 1st.

D09456

Hand–held Tester

DLC3

–

DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

DI–211

LEXUS RX300   (RM785E)

(11) After doing the check, disconnect the SST from ter-

minals Ts and CG, Tc and CG of DLC3 and turn the
ignition switch OFF.

SST

09843–18040

(d)

In case of using hand–held tester:
Check the VSC sensor signal.
(1)

Hook up the hand–held tester to the DLC3.

(2)

Do steps (2) and (4) to (8) on the previous pages.

(3)

Read the DTC by following the prompts on the tes-
ter screen.

HINT:
Please refer to the hand–held tester operator’s manual for fur-
ther details.

DTC of VSC sensor check function:

Code No.

Diagnosis

Trouble Area

C0371 / 71

Yaw rate sensor output signal malfunction

S Yaw rate sensor

S Yaw rate sensor circuit

C1208 / 72

Steering angle sensor output signal malfunction

S Steering angle sensor

S Steering angle sensor circuit

3.

YAW RATE SENSOR ZERO POINT CALIBRATION

HINT:
When replacing the yaw rate sensor assembly or ECU, make
sure to perform yaw rate sensor zero point calibration.
Perform yaw rate sensor zero point calibration.

(1)

Shift the shift lever in P range and turn the ignition
switch ON, repeat connecting and releasing Ts and
CG terminals of DLC3 4 times or more for 8 sec.

HINT:
When operation (1) is performed, DTC is deleted.

(2)

Do not move the vehicle for 15 sec. or more.

HINT:
At this time VSC warning light is on for 15 sec. and goes off, and
zero point calibration for yaw rate sensor is completed.
4.

DECELERATION SENSOR OPERATION DIAGNOSIS
SYSTEM

CAUTION:
While checking the deceleration sensor operating diagno-
sis system, ABS does not work and break system works as
a conventional break system.