Toyota Sequoia (2005). Manual - part 890

BE0FZ–25

I24377

I24378

I04197

–

BODY ELECTRICAL

HORN SYSTEM

BE–145

3549

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.
3.

INSPECT HORN SWITCH CIRCUIT
(See page 

DI–1764

)

I01200

2

1

3

5

2

5

1

3

BE–146

–

BODY ELECTRICAL

HORN SYSTEM

3550

4.

INSPECT HORN RELAY CONTINUITY

Condition

Tester connection

Specified condition

Always

1 – 2

Continuity

Always

3 – 5

No continuity

Apply B+ between

terminals 1 and 2.

3 – 5

Continuity

If continuity is not as specified, replace the relay.
5.

INSPECT HORN RELAY CIRCUIT
(See page 

DI–1764

)

BE26G–04

I28424

Engine Room J/B

 TOWING Fuse

Trailer Socket

Towing Converter Relay
(Located inside of the quarter trim panel LH)

Engine Room R/B No. 3

 BATT CHARGE Relay

 TOWING TAIL Relay

 TOWING BRK Fuse

 TOWING TAIL Fuse

Brake Controller
(Located inside of the cowl side trim board LH)

–

BODY ELECTRICAL

TRAILER TOWING

BE–147

3551

TRAILER TOWING

LOCATION

BE2D5–02

I24381

Wire Harness Side:

BE–148

–

BODY ELECTRICAL

TRAILER TOWING

3552

INSPECTION

1.

INSPECT TOWING CONVERTER CIRCUIT

Remove the towing converter with the connector still connected
and inspect the wire harness side connector from the back side,
as shown in the table below.

Tester connection

Condition

Specified condition

4 – 6

Turn signal switch LEFT or hazard warning switch ON

10 – 14

 

V 

↔

 0 V

4 – 6

Turn signal switch LEFT and stop light switch ON (Brake pedal depressed)

10 – 14 V 

↔

 0 V

4 – 6

Turn signal switch OFF, hazard warning switch OFF and stop light switch OFF

(Brake pedal released)

0 V

4 – 6

Stop light switch ON (Brake pedal depressed)

10 – 14

 

V

6 – 9

Turn signal switch LEFT or hazard warning switch ON

10 – 14

 

V 

↔

 0 V

6 – 9

Turn signal switch OFF or RIGHT and hazard warning switch OFF

0 V

6 – Body ground

Always

Continuity

2 – 6

Turn signal switch RIGHT or hazard warning switch ON

10 – 14

 

V 

↔

 0 V

2 – 6

Turn signal switch RIGHT and stop light switch ON (Brake pedal depressed)

10 – 14 V 

↔

 0 V

2

6

Turn signal switch OFF, and hazard warning switch OFF and stop light switch OFF

0 V

2 – 6

Turn signal switch OFF, and hazard warning switch OFF and sto  light switch OFF

(Brake pedal released)

0 V

2 – 6

Stop light switch ON (Brake pedal depressed)

10 – 14 V 

↔

 0 V

1 – 6

Always

10 – 14 V

6 – 8

Stop light switch ON (Brake pedal depressed)

10 – 14 V

6 – 8

Stop light switch OFF (Brake pedal released)

0 V

3 – 6

Turn signal switch RIGHT or hazard warning switch ON

10 – 14

 

V 

↔

 0 V

3 – 6

Turn signal switch OFF or LEFT and hazard warning switch OFF

0 V

If the circuit is not as specified, inspect the circuit connected to
other parts.