Lexus RX300 (MCU15). Manual — part 161

BE0FY–20

I19138

Horn Switch

Engine Room J/B
D HORN Fuse
D HORN Relay

Horn

–

BODY ELECTRICAL

HORN SYSTEM

BE–191

LEXUS RX300 (RM785E)

HORN SYSTEM

LOCATION

BE0FZ–16

I07339

I07340

6

BE3907

BE–192

–

BODY ELECTRICAL

HORN SYSTEM

LEXUS RX300 (RM785E)

INSPECTION

1.

INSPECT HORN SWITCH

(a)

Disconnect the negative (–) terminal from the battery.

(b)

Remove the left and right covers from the steering wheel.

(c)

Using a torx socket wrench, loosen the 2 bolts.

(d)

Pull up the horn pad and place it on the steering column,
as shown.

HINT:
Do not disconnect the connector from the horn pad.
(e)

Disconnect the connector from the slip ring.

(f)

Check that no continuity exists between terminal 6 of the
connector and body ground.

(g)

Check that continuity exists between terminal 6 of the
connector and body ground when the horn contact plate
is pressed against the steering spoke assembly.

If continuity is not as specified, repair or replace the steering
wheel or wire harness as necessary.
(h)

Install the horn pad in place and using a torx socket
wrench, torque the 2 bolts.
Torque:

7.1 N·m (72 kgf·cm, 62 in.·lbf)

(i)

Install the left and right covers.

(j)

Connect the negative (–) terminal to the battery.

2.

INSPECT HORN OPERATION

Connect the positive (+) lead from the battery to the terminal
and negative (–) lead to the horn body and check that the horn
blows.
If operation is not as specified, replace the horn.

I01200

2

1

3

5

2

5

1

3

–

BODY ELECTRICAL

HORN SYSTEM

BE–193

LEXUS RX300 (RM785E)

3.

INSPECT HORN RELAY CONTINUITY

Condition

Tester connection

Specified condition

Constant

1 – 2

Continuity

Apply B+ between

terminals 1 and 2.

3 – 5

Continuity

If continuity is not as specified, replace the relay.
4.

INSPECT HORN RELAY CIRCUIT
(See page BE–18)

BRAKE

BRAKE SYSTEM

BR–1

. . . . . . . . . . . . . . . . . . . . . . . .

TROUBLESHOOTING

BR–2

. . . . . . . . . . . . . . . . . . . .

BRAKE FLUID

BR–4

. . . . . . . . . . . . . . . . . . . . . . . . . . .

BRAKE PEDAL

BR–6

. . . . . . . . . . . . . . . . . . . . . . . . . .

PARKING BRAKE PEDAL

BR–8

. . . . . . . . . . . . . . . . .

BRAKE MASTER CYLINDER

BR–14

. . . . . . . . . . . . . .

BRAKE BOOSTER ASSEMBLY

BR–23

. . . . . . . . . . . .

FRONT BRAKE PAD

BR–29

. . . . . . . . . . . . . . . . . . . . .

FRONT BRAKE CALIPER

BR–32

. . . . . . . . . . . . . . . . .

REAR BRAKE PAD

BR–40

. . . . . . . . . . . . . . . . . . . . . . .

REAR BRAKE CALIPER

BR–43

. . . . . . . . . . . . . . . . . .

PARKING BRAKE

BR–49

. . . . . . . . . . . . . . . . . . . . . . . .

PROPORTIONING VALVE (P VALVE)

BR–53

. . . . . .

BRAKE ACTUATOR

BR–54

. . . . . . . . . . . . . . . . . . . . . .

FRONT SPEED SENSOR

BR–58

. . . . . . . . . . . . . . . . .

REAR SPEED SENSOR

BR–61

. . . . . . . . . . . . . . . . . .