Lexus ES300 (1997 year). Service manual - part 380

F00108

Battery

MAIN

FL Block

ALT

B–G

AM1

1K

2

Ignition 
Switch

Instrument Panel J/B

1B

F6

F11

1

A20

GND3

B–R

1

Instrument Panel J/B

1

A19

B–Y

J/C

ECU–IG

4

B–R

A

ABS & TRAC ECU

9

A21

1J

J3

IG1

W–B

W

GND1

GND2

2

1K

1

A

B–R

A21

W–B

W–B

W–B

W–B

W–B

EA

8

15

EB

10

9

W–B

Battery

MAIN

FL Block

ALT

B–G

AM1

1K

2

Ignition 
Switch

Instrument Panel J/B

1B

F6

F11

1

A20

GND3

B–R

1

Instrument Panel J/B

1

A19

B–Y

J/C

ECU–IG

4

B–R

A

ABS & TRAC ECU

9

A21

1J

J3

IG1

W–B

W

GND1

GND2

2

1K

1

A

B–R

A21

W–B

W–B

W–B

W–B

W–B

EA

8

15

EB

10

9

W–B

Battery

MAIN

FL Block

ALT

B–G

AM1

1K

2

Ignition 
Switch

Instrument Panel J/B

1B

F6

F11

1

A20

GND3

B–R

1

Instrument Panel J/B

1

A19

B–Y

J/C

ECU–IG

4

B–R

A

ABS & TRAC ECU

9

A21

1J

J3

IG1

W–B

W

GND1

GND2

2

1K

1

A

B–R

A21

W–B

W–B

W–B

W–B

W–B

EA

8

15

EB

10

9

W–B

Battery

MAIN

FL Block

ALT

B–G

AM1

1K

2

Ignition 
Switch

Instrument Panel J/B

1B

F6

F11

1

A20

GND3

B–R

1

Instrument Panel J/B

1

A19

B–Y

J/C

ECU–IG

4

B–R

A

ABS & TRAC ECU

9

A21

1J

J3

IG1

W–B

W

GND1

GND2

2

1K

1

A

B–R

A21

W–B

W–B

W–B

W–B

W–B

EA

8

15

EB

10

9

W–B

Battery

MAIN

FL Block

ALT

B–G

AM1

1K

2

Ignition 
Switch

Instrument Panel J/B

1B

F6

F11

1

A20

GND3

B–R

1

Instrument Panel J/B

1

A19

B–Y

J/C

ECU–IG

4

B–R

A

ABS & TRAC ECU

9

A21

1J

J3

IG1

W–B

W

GND1

GND2

2

1K

1

A

B–R

A21

W–B

W–B

W–B

W–B

W–B

EA

8

15

EB

10

9

W–B

–

DIAGNOSTICS

ABS & TRACTION CONTROL SYSTEM

DI–297

449

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

Detection of any conditions from (1) through (3):

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

   voltage is less than 9.5 V continues for 10 sec. or 

    more.

(2) Battery voltage has never exceeded more than 17.0 V

     and has become less than 9.5 V within 2.16 sec., under

     malfunction of solenoid relay monitor after the solenoid

   relay is ON, at ECU AST terminal voltage of ECU has

  become 8.0 V or more or under malfunction of motor

 relay monitor and after the motor relay is ON, motor

relay monitor has become ON.

(3) Battery voltage is more than 17.0 V continues for 1.2

    sec. or more or battery voltage has become more than

   17.0 V within 2.16 sec. and solenoid or motor relay

  monitor is under malfunction condition.

Battery

IC regulator

Power source circuit

ECU

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

WIRING DIAGRAM

DI0C6–01

F00058

IG1

GND

ON

(+)

(–)

IG1

GND

ON

(+)

(–)

IG1

GND

ON

(+)

(–)

IG1

GND

ON

(+)

(–)

F00059

GND

(+)

(–)

LOCK

GND

(+)

(–)

LOCK

GND

(+)

(–)

LOCK

GND

(+)

(–)

LOCK

DI–298

–

DIAGNOSTICS

ABS & TRACTION CONTROL SYSTEM

450

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 & TRAC ECU connector.

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

Turn the ignition switch ON.

(b)

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

OK:

Voltage: 10 – 14 V

NG

Check and replace ABS & TRAC ECU.

OK

3

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

CHECK:
Measure resistance between terminal GND of ABS & TRAC
ECU connector 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

–

DIAGNOSTICS

ABS & TRACTION CONTROL SYSTEM

DI–299

451

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 & TRAC ECU and battery 
(See page 

IN–27

).

DI–300

–

DIAGNOSTICS

ABS & TRACTION CONTROL SYSTEM

452

1997 LEXUS ES300   (RM511U)

DTC

43

ABS Control System Malfunction

CIRCUIT DESCRIPTION

DTC No.

DTC Detecting Condition

Trouble Area

43

Detection of any conditions from (1) through (8):

(1) During TRAC is in non–operation and ABS is 

     output DTC, but TRAC is not during initial lamp

     checking, terminal WA of ECU is ON and engine 

     speed is 500 rpm or more continues for 1 sec. or 

     more.

(2) Solenoid relay circuit is open or short.

(3) Motor relay circuit is open or short.

(4) ABS solenoid circuit is open or short.

(5) TRAC solenoid circuit is open or short.

(6) Speed sensor is under malfunction condition.

(7) IG power source is down or raise.

(8) Pump motor is lock.

ABS control system

INSPECTION PROCEDURE

1

Check the DTC for the ABS (See page 

DI–273

).

*1

Repair ABS control system according to the
code output.

*2

Check for ECU connected to malfunction indicator lamp.

*1: Output NG code
*2: Malfunction indicator lamp remains ON.

DI0C7–01