Lexus ES300 (1997 year). Manual — part 369

–

DIAGNOSTICS

ANTI–LOCK BRAKE SYSTEM

DI–253

405

1997 LEXUS ES300 (RM511U)

DTC

33, 34

Rear Speed Sensor Rotor Faulty

CIRCUIT DESCRIPTION

DTC No.

DTC Detecting Condition

Trouble Area

33, 34

The condition that both rear side wheels’ speed is lower

than front wheels’ speed at 20 km/h (12 mph) or more for

20 sec. or more when IG switch turns ON and OFF is

repeated in a sequence more than 8 times.

Rear axle hub

Right rear, left rear speed sensor

Rear speed sensor circuit

INSPECTION PROCEDURE

1

Check rear axle hub (See page

SA–45

).

NG

Replace rear axle hub.

OK

2

Check rear speed sensor (See page

DI–248

).

NG

Replace rear speed sensor.

OK

3

Check for open or short in harness and connector between rear speed sensor
and ECU (See page

IN–27

).

NG

Repair or replace harness and connector.

OK

Check and replace ABS ECU.

DI0BM–01

F00110

Battery

MAIN

B–G

FL Block

ALT

B–R

F6

F11

1

1

AM1

Instrument Panel J/B

Instrument Panel J/B

1B

1K

1

2

W

Ignition
Switch

4

2

B–Y

1K

1J

1

9

ECU–IG

B–R

B–R

A

A

J/C

J3

A22

A23

A23

ABS ECU

IG1

GND1

2

GND2

2

13

W–B

W–B

W–B

W–B

W–B

EA

EB

Battery

MAIN

B–G

FL Block

ALT

B–R

F6

F11

1

1

AM1

Instrument Panel J/B

Instrument Panel J/B

1B

1K

1

2

W

Ignition
Switch

4

2

B–Y

1K

1J

1

9

ECU–IG

B–R

B–R

A

A

J/C

J3

A22

A23

A23

ABS ECU

IG1

GND1

2

GND2

2

13

W–B

W–B

W–B

W–B

W–B

EA

EB

Battery

MAIN

B–G

FL Block

ALT

B–R

F6

F11

1

1

AM1

Instrument Panel J/B

Instrument Panel J/B

1B

1K

1

2

W

Ignition
Switch

4

2

B–Y

1K

1J

1

9

ECU–IG

B–R

B–R

A

A

J/C

J3

A22

A23

A23

ABS ECU

IG1

GND1

2

GND2

2

13

W–B

W–B

W–B

W–B

W–B

EA

EB

Battery

MAIN

B–G

FL Block

ALT

B–R

F6

F11

1

1

AM1

Instrument Panel J/B

Instrument Panel J/B

1B

1K

1

2

W

Ignition
Switch

4

2

B–Y

1K

1J

1

9

ECU–IG

B–R

B–R

A

A

J/C

J3

A22

A23

A23

ABS ECU

IG1

GND1

2

GND2

2

13

W–B

W–B

W–B

W–B

W–B

EA

EB

Battery

MAIN

B–G

FL Block

ALT

B–R

F6

F11

1

1

AM1

Instrument Panel J/B

Instrument Panel J/B

1B

1K

1

2

W

Ignition
Switch

4

2

B–Y

1K

1J

1

9

ECU–IG

B–R

B–R

A

A

J/C

J3

A22

A23

A23

ABS ECU

IG1

GND1

2

GND2

2

13

W–B

W–B

W–B

W–B

W–B

EA

EB

DI–254

–

DIAGNOSTICS

ANTI–LOCK BRAKE SYSTEM

406

1997 LEXUS ES300 (RM511U)

DTC

41

IG Power Source Circuit

CIRCUIT DESCRIPTION

This is the power source for the ECU, hence the actuators.

DTC No.

DTC Detecting Condition

Trouble Area

41

Condition (1) or (2) is detected:

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

ECU terminal IG1 voltage is 9.5 V or less continues for

10 sec. or more.

(2) While ABS solenoid or motor relay is ON, ABS ECU

terminal IG1 voltage becomes 9.5 V or less and when

ABS ECU terminal AST or MT voltage is less than 4 V

continues for 0.2 sec. or more.

Battery

IC regulator

Power source circuit

Fail safe function: If trouble occurs in the power source circuit, the ECU cuts off current to the ABS solenoid
relay and prohibits ABS control.

WIRING DIAGRAM

DI0BN–01

F00045

ON

(+)

(–)

IG1

GND

GND

ON

(+)

(–)

IG1

GND

GND

ON

(+)

(–)

IG1

GND

GND

ON

(+)

(–)

IG1

GND

GND

F00046

LOCK

(+)

(–)

GND

LOCK

(+)

(–)

GND

LOCK

(+)

(–)

GND

LOCK

(+)

(–)

GND

–

DIAGNOSTICS

ANTI–LOCK BRAKE SYSTEM

DI–255

407

1997 LEXUS ES300 (RM511U)

INSPECTION PROCEDURE

1

Check battery positive voltage.

OK:

Voltage: 10 – 14 V

NG

Check and repair the charging system.

OK

2

Check voltage between terminals IG1 and GND of ABS ECU connector.

PREPARATION:
Remove ABS ECU with connectors still connected.
CHECK:
(a)

Turn the ignition switch ON.

(b)

Measure voltage between terminals IG1 and GND of ABS
ECU connector.

OK:

Voltage: 10 – 14 V

NG

Check and replace ABS ECU.

OK

3

Check continuity between terminals GND of ABS ECU connector and body
ground.

CHECK:
Measure resistance between terminal GND of ABS ECU con-
nector and body ground.
OK:

Resistance: 1

Ω

or less

NG

Repair or replace harness or connector.

OK

F00073

Instrument
Panel J/B

ECU–IG

Instrument
Panel J/B

ECU–IG

Instrument
Panel J/B

ECU–IG

DI–256

–

DIAGNOSTICS

ANTI–LOCK BRAKE SYSTEM

408

1997 LEXUS ES300 (RM511U)

4

Check ECU–IG fuse.

PREPARATION:
Remove ECU–IG fuse from Instrument Panel J/B.
CHECK:
Check continuity of ECU–IG fuse.
OK:

Continuity

NG

Check for short in all the harness and compo-
nents connected to ECU–IG fuse (See attached
wiring diagram.

OK

Check for open in harness and connector between ABS ECU and battery (See page

IN–27

).