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:
Reassembly
1. INSTALL UNDERDRIVE CLUTCH DRUM O-RING
(a) Coat a new O-ring with ATF, and install it to the
underdrive clutch drum.
NOTICE:
Make sure that the O-ring is not twisted or
pinched.
2. INSTALL UNDERDRIVE CLUTCH PISTON SET
(a) Coat the underdrive clutch piston with ATF, and
install it t ...
AVC-LAN Circuit
DESCRIPTION
Each unit of the navigation system connected to the AVC-LAN (communication
bus) transfers the signal of
each switch by communication.
When a short to +B or short to ground occurs in this AVC-LAN, the navigation
system will not function
normally as the communication is discontin ...
Past record
Type A
Press the “CAR” button.
Type B
Press the “APPS” button, and then select “Eco” on the screen.
If the “Trip Information” screen is displayed, select “Past Record”.
Reset the past record data
Best recorded fuel consumption
Average fuel consumption ...
