Lexus RX300 (MCU15). Service manual — part 256

DI–256

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DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

LEXUS RX300 (RM785E)

INSPECTION PROCEDURE

HINT:
Start the inspection from step 1 in case of using the hand–held tester and start from step 3 in case of not
using the hand–held tester.

1

Check output value of the steering angle sensor.

PREPARATION:
(a)

Connect the hand–held tester to the DLC3.

(b)

Turn the ignition switch ON and push the hand–held tester main switch ON.

(c)

Select the DATALIST mode on the hand–held tester.

(d)

Drive the vehicle straight forward at 35 km/h (22 mph) or more for 1 second or longer.

HINT:

S

At this time, the zero point calibration of the steering angle sensor was memorized.

S

Do not stop the engine.

CHECK:
Check that the steering wheel turning angle value of the steering angle sensor displayed by the hand–held
tester is changing when turning the steering wheel.
OK:

Steering wheel turning angle value must be changing.

OK

Go to step 3.

NG

2

Replace the skid control ECU and check whether or not the trouble occurs
again.

YES

Replace steering angle sensor.

NO

END

F03003

1

2

6

3

(+)

(–)

(+)

(–)

(Oscilloscope)

LOCK

F03008

(Reference)

3 ms

2,288 µs

100 µs

5 V

0 V

5 V

0 V

ÇÇÇ

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DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

DI–257

LEXUS RX300 (RM785E)

3

Check steering angle sensor.

PREPARATION:
(a)

Remove the steering wheel lower No. 2 and No. 3 covers,
steering wheel pad, steering wheel, column upper and
lower covers (See page SR–10).

(b)

Disconnect the connector from the steering angle sensor.

(c)

Connect the oscilloscope to the terminals 3 and 6 of the
combination switch connector (for steering angle sensor).

(d)

Apply battery voltage between terminals 1 and 2.

CHECK:
Turn the steering wheel slowly and check the signal waveform.
OK:

HINT:
The above signal waveform does not repeat ON and OFF regu-
larly and this combination changes case by case according to
the data.

NG

Replace steering angle sensor.

OK

4

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

NG

Repair or replace harness or connector.

OK

Check and replace skid control ECU.

DI–258

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DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

LEXUS RX300 (RM785E)

DTC

C1232 / 32

Deceleration Sensor Circuit

CIRCUIT DESCRIPTION

DTC No.

DTC Detecting Condition

Trouble Area

C1232 / 32

Detection of any of conditions 1. through 2. :

1. At the vehicle speed of 10 km/h (6 mph) or more, the

condition that ECU terminal GL1 signal change range is

less than 20 mV continues for 30 sec., and ECU termi-

nal GL2 signal change range swings by 0.47 V or more.

2. At the vehicle speed of 10 km/h (6 mph) or more, the

condition that ECU terminal GL2 signal change range is

less than 20 mV continues for 30 sec., and ECU termi-

nal GL1 signal change range swings by 0.47 V or more.

S Deceleration sensor

S Deceleration sensor circuit

INSPECTION PROCEDURE

HINT:
Start the inspection from step 1 in case of using the hand–held tester and start from step 2 in case of not
using the hand–held tester.

1

Check output value of the deceleration sensor.

PREPARATION:
(a)

Connect the hand–held tester to the DLC3.

(b)

Turn the ignition switch ON and push the hand–held tester main switch ON.

(c)

Select the DATALIST mode on the hand–held tester.

CHECK:
Check that the deceleration value of the deceleration sensor displayed by the hand–held tester is changing
when tilting the vehicle.
OK:

Deceleration value must be changing.

OK

Check and replace skid control ECU.

NG

2

Check deceleration sensor (See page DI–205).

NG

Replace deceleration sensor assembly.

OK

DI1H6–06

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DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

DI–259

LEXUS RX300 (RM785E)

3

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

NG

Repair or replace harness and connector.

OK

Check and replace skid control ECU.