Inspection Procedure

WARNING: This page is about a different car, the 2008 Toyota Yaris. However, it is still accessible from the selected car via links, so may be relevant.

PERFORM ACTIVE TEST USING TECHSTREAM (SECURITY HORN)

Connect the Techstream to the DLC3.
Turn the ignition switch ON.
Turn the tester ON.

Select the item below in the Active Test and then check that the horn operates.

Theft Warning ECU

THEFT WARNING ECU TABLE

Item	Test Details
Security Horn	Security horn ON/OFF

OK: Security horn operates normally.

NG: Go to step 2

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

INSPECT FUSE (ECU-B)
1. Remove the ECU-B fuse from the engine room R/B.
2. Measure the resistance.
  Standard resistance: Below 1 Ω
3. Reinstall the ECU-B fuse.
NG: REPLACE FUSE

OK: GO TO NEXT STEP

CHECK HARNESS AND CONNECTOR (THEFT WARNING ECU ASSEMBLY-BODY GROUND)

Disconnect the D26 theft warning ECU connector.

Measure the voltage.

Standard voltage

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Specified Condition
D26-13 (+B2) - Body ground	11 to 14 V

Reconnect the theft warning ECU connector.

Fig 2: Checking Harness & Connector (Theft Warning ECU Assembly-Body Ground)

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NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: GO TO NEXT STEP

INSPECT SECURITY HORN ASSEMBLY

Disconnect the A23 security horn connector.

Check the operation of the security horn.

Standard

MEASUREMENT AND SPECIFIED CONDITION TABLE

Measurement Condition	Specified Condition
Battery positive (+}→Terminal 1 Battery negative (-)→Terminal 2	Security horn sounds

Reconnect the security horn connector.

Fig 3: Checking Operation Of Security Horn

NG: REPLACE SECURITY HORN ASSEMBLY

OK: GO TO NEXT STEP

CHECK HARNESS AND CONNECTOR (THEFT WARNING ECU ASSEMBLY - SECURITY HORN ASSEMBLY)

Disconnect the D26 theft warning ECU and the A23 security horn connectors.

Measure the resistance.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Specified Condition
D26-15 (SH-) - A23-1	Below 1 Ω
A23-2 - Body ground	Below 1 Ω
D26-15 (SH-) or (A23-1) - Body ground	10 kΩ or higher

Reconnect the theft warning ECU and the security horn connectors.

Fig 4: Checking Harness & Connector (Theft Warning ECU Assembly - Security Horn Assembly)

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE THEFT WARNING ECU ASSEMBLY