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:
Removal
1. REMOVE REAR WHEEL
2. REMOVE REAR SHOCK ABSORBER CAP LH
(a) Remove the shock absorber head cover.
(b) Remove the shock absorber cap LH.
3. REMOVE SHOCK ABSORBER ASSEMBLY REAR LH
(a) Support the rear axle beam with a jack.
(b) Using a 6 mm hexagon wrench to hold the piston
rod, ...
Installation
1. INSTALL ENGINE COOLANT TEMPERATURE SENSOR
Install the engine coolant temperature sensor.
Torque: 20 N*m (204 kgf*cm, 15 ft.*lbf)
Connect the engine coolant temperature sensor
connector.
2. INSTALL AIR CLEANER CASE SUB-ASSEMBLY
3. INSTALL AIR CLEANER CAP SUB-ASSEMBLY
...
System description
1. OUTLINE OF THEFT DETERRENT SYSTEM
When the theft deterrent system detects that the
vehicle is being tampered with, the system sets off
the alarm, causing the horns to sound and the lights
to light up or blink in order to alert people around the
vehicle to the theft.
The ...
