Lexus RX300 (MCU15). Service manual - part 259

DI–268

–

DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

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 or connector.

OK

Check and replace skid control ECU.

F06955

Deceleration Sensor

Skid Control ECU

GL1

(Shielded)

1

VGS

GSS

A22

GL2

GGND

GGND

GL2

GL1

VGS

2

9

10

18

1

2

3

5

B

W

R

G

A22

A22

A22

A22

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DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

DI–269

LEXUS RX300   (RM785E)

DTC

C1244 / 44

Deceleration Sensor Circuit

CIRCUIT DESCRIPTION

This sensor detects deceleration on the vehicle. The sensor signal is used in ABS & BA & TRC & VSC  con-
trol. If the sensor functions abnormally, the ABS warning light comes on.

DTC No.

DTC Detecting Condition

Trouble Area

C1244 / 44

Either of the following 1., 2., 3. or 4. is detected:

1. The condition that ECU terminals GL1 and GL2 G conver-

sion values are –1.5 G or less or 1.5 G or more continues

for 1.2 sec. or more.

2. The condition that the deceleration sensor terminal VGS

voltage is 4.4 V or less or 5.6 V or more continues for 1.2

sec. or more.

3. At the vehicle speed of 0 km/h (0 mph), after the difference

of output absolute value of G conversion value between

deceleration sensor terminals GL1 and GL2 becomes 0.6 G

or more, and the condition that does not become 0.4 G con-

tinues for 60 sec. or more.

4. Deceleration sensor signal momentary open occurs for 7

times or more.

S Deceleration sensor

S Deceleration sensor circuit

WIRING DIAGRAM

DI1GM–06

DI–270

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DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

LEXUS RX300   (RM785E)

INSPECTION PROCEDURE

1

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

NG

Repair or replace harness or connector.

OK

2

Check deceleration sensor (See page DI–205).

NG

Replace deceleration sensor.

OK

Check and replace skid control ECU.

F06952

Master Cylinder 
Pressure Sensor

Skid Control ECU

FSS

VCM

E2

22

PMC

10

23

1

2

3

24

VCM

PMC

E2

A21

(Shielded)

B

W

R

A21

A21

A21

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DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

DI–271

LEXUS RX300   (RM785E)

DTC

C1246 / 46

Master Cylinder Pressure Sensor 
Circuit

CIRCUIT DESCRIPTION

DTC No.

DTC Detecting Condition

Trouble Area

C1246 / 46

Either of the following 1., 2., 3., 4. or 5. is detected:

1. When the vehicle speed is 7 km/h (4.3 mph) and ECU

terminal PMC voltage is 0.86 V or more, the condition

that the terminal voltage does not change by more than

0.005 V continues for 30 sec.

2. The noise to ECU terminal PMC occurs 7 times for 5

secs.

3. When ECU terminal STP is OFF, the condition that ECU

terminal PMC voltage is 0.86 or more or 0.3 V or less

continues for more than 5 sec.

4. When the ECU terminal IG1 is 9.5 V to 17.2 V the condi-

tion that ECU terminal VCM voltage is out of range of

4.4 V to 5.6 V continues for 1.2 sec.

5. When ECU terminal VCM voltage is 4.4 V to 5.6 V the

condition that ECU terminal PMC voltage is out of range

of 0.14 V to 4.85 V continues for more than 1.2 sec.

S Master cylinder pressure sensor

S Master cylinder pressure sensor circuit

WIRING DIAGRAM

DI1GN–06