Toyota Sienna Service Manual: ECU Power Source Circuit
DESCRIPTION
This is the power source for the tire pressure warning ECU.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE: When replacing the tire pressure warning ECU, read the transmitter IDs stored in the old ECU using the intelligent tester and write them down before removal.
It is necessary to register an ID code after replacing the tire pressure warning valve and transmitter and/or the tire pressure warning ECU (See page TW-20).
1 INSPECT FUSE (ECU-IG)
(a) Remove the ECU-IG fuse from the instrument panel junction block.
(b) Measure the resistance of the fuse.
Standard resistance: Below 1 Ω
2 INSPECT IGNITION RELAY NO. 1
(a) Remove the IG1 relay from the instrument panel junction block.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance 
3 CHECK HARNESS AND CONNECTOR (ECU - BATTERY AND BODY GROUND)
(a) Disconnect the T15 ECU connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage 
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE (See page TW-28)
Tire Pressure Warning Light Circuit
DESCRIPTION
If the ECU detects trouble, the tire pressure warning light blinks (comes on
after blinking for 1 minute) and
tire pressure monitor is cancelled at the same time. At this time, the ECU ...
TC and CG Terminal Circuit
DESCRIPTION
DTC output mode is set by connecting terminals 13 (TC) and 4 (CG) of the
DLC3. The DTCs are indicated
by blinks of the tire pressure warning light.
WIRING DIAGRAM
HINT:
When eac ...
Other materials:
Installation
HINT:
Install the RH side by the same procedures with LH side.
1. INSTALL FRONT SPEED SENSOR LH
(a) Install the speed sensor front LH with the bolt.
Torque: 8.0 N*m (82 kgf*cm, 71 in.*lbf)
NOTICE:
Keep the tip of the front speed sensor LH.
(b) Install the sensor harness clamps with th ...
Airbag ECU Communication Stop
DTC B1281 Airbag ECU Communication Stop
DESCRIPTION
DTC B1281 is output when communication between the airbag ECU and the
multiplex network gateway
ECU stops for more than 10 seconds.
DTC No.
DTC Detection Condition
Trouble Area
B1281
Airbag ECU communi ...
Sound setting
Display the “Phone/Message Settings” screen.
Select “Sound Settings” on the “Phone/Message Settings” screen.
Set the desired ringtone.
Adjust the ringtone volume.
Adjust the message readout
volume.
Set the desired incoming
SMS/MMS tone.
Adjust the incoming SMS ...
