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.

NOTE:

When replacing the tire pressure warning ECU, read the IDs stored in the old ECU using a Techstream and write them down before removal.
It is necessary to perform registration (See REGISTRATION ) of the transmitter IDs into the tire pressure warning ECU after the ECU has been replaced.

INSPECT FUSE (ECU-IG)

Remove the ECU-IG fuse from the main body ECU.

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

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Condition	Specified Condition
ECU-IG	Always	Below 1 Ω

Fig 1: Identifying ECU-IG Fuse

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Go to step 4

OK: Go to Next Step

CHECK HARNESS AND CONNECTOR (TIRE PRESSURE WARNING ECU - BATTERY)

Disconnect the D78 ECU connector.

Fig 2: Checking Harness And Connector (Tire Pressure Warning ECU - Battery)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard voltage

VOLTAGE SPECIFICATION

Tester Connection	Switch Condition	Specified Condition
D78-7 (IG) - Body ground	Ignition switch ON	11 to 14 V
D78-7 (IG) - Body ground	Ignition switch OFF	Below 1 V

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next Step

CHECK HARNESS AND CONNECTOR (TIRE PRESSURE WARNING ECU - BODY GROUND)

Disconnect the D78 ECU connector.

Fig 3: Checking Harness And Connector (Tire Pressure Warning ECU - Body Ground)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Condition	Specified Condition
D78-9 (GND) - Body ground	Always	Below 1 Ω

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE TIRE PRESSURE WARNING ECU (See TIRE PRESSURE WARNING ECU )

CHECK HARNESS AND CONNECTOR (TIRE PRESSURE WARNING ECU - FUSE)

Disconnect the D78 ECU connector.

Fig 4: Checking Harness And Connector (Tire Pressure Warning ECU - Fuse)

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

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Switch Condition	Specified Condition
D78-7 (IG) - Body ground	Ignition switch OFF	10 kΩ or higher

NG: REPLACE FUSE AND REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE FUSE