THEFT DETERRENT / KEYLESS ENTRY: THEFT DETERRENT SYSTEM: Security Horn Circuit; 2017 - 2020 MY Sienna [08/2016

Last Modified: 04-05-2023	6.11:8.1.0	Doc ID: RM100000000ZL67
Model Year Start: 2017	Model: Sienna	Prod Date Range: [08/2016 - ]
Title: THEFT DETERRENT / KEYLESS ENTRY: THEFT DETERRENT SYSTEM: Security Horn Circuit; 2017 - 2020 MY Sienna [08/2016 - ]

Security Horn Circuit

DESCRIPTION

When the theft deterrent system is switched from the armed state to the alarm sounding state, the main body ECU controls the security horn assembly.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1.	PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Select the item below in the Active Test and then check that the security horn assembly operates.

Main Body

Tester Display	Test Part	Control Range	Diagnostic Note
Security Horn	Security horn	ON/OFF	-

OK:

The security horn assembly sounds and stops correctly when operated through the Techstream.

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

2.	INSPECT SECURITY HORN ASSEMBLY

(a) Remove the security horn assembly (See page ).

(b) Inspect the security horn assembly (See page ).

REPLACE SECURITY HORN ASSEMBLY

3.	INSPECT S-HORN RELAY

(a) Remove the S-HORN relay from the No. 3 relay block.

(b) Inspect the S-HORN relay (See page ).

REPLACE S-HORN RELAY

4.	INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Remove the main body ECU (See page ).

*1	Component without harness connected (Instrument Panel Junction Block Assembly)

(b) Disconnect the instrument panel junction block assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
2F-24 - 2I-17 (SH)	Always	Below 1 Ω

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

5.	CHECK HARNESS AND CONNECTOR (BATTERY - S-HORN RELAY)

(a) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Condition	Specified Condition
1 (S-HORN relay) - Body ground	Always	11 to 14 V
3 (S-HORN relay) - Body ground	Always	11 to 14 V

*1	No. 3 Relay Block
*2	S-HORN Relay Holder

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.	CHECK HARNESS AND CONNECTOR (S-HORN RELAY - SECURITY HORN ASSEMBLY)

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
5 (S-HORN relay) - A14-1	Always	Below 1 Ω
5 (S-HORN relay) - Body ground	Always	10 kΩ or higher
A14-1 - Body ground	Always	10 kΩ or higher

*1	No. 3 Relay Block
*2	S-HORN Relay Holder

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.	CHECK HARNESS AND CONNECTOR (S-HORN RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
2 (S-HORN relay) - 2F-24	Always	Below 1 Ω
2 (S-HORN relay) - Body ground	Always	10 kΩ or higher
2F-24 - Body ground	Always	10 kΩ or higher

*1	No. 3 Relay Block
*2	S-HORN Relay Holder

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

REPAIR OR REPLACE HARNESS OR CONNECTOR