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:
Under hood
GENERAL MAINTENANCE
1. GENERAL NOTES
Maintenance requirements very depending on the
country.
Check the maintenance schedule in the owner's
manual supplement.
Following the maintenance schedule is mandatory.
Determine the appropriate time to service the vehicle
using either miles dri ...
Drive information
Items displayed can be switched
by pressing the “DISP” switch.
Current fuel economy
Displays the current rate of fuel consumption.
Use the displayed current fuel consumption as a reference.
Average fuel economy
Displays the average fuel consumption since the function was reset
...
Removal
1. REMOVE BATTERY (See page EM-26)
2. REMOVE NO. 2 AIR CLEANER INLET (See page EM-
28)
3. REMOVE AIR CLEANER CAP SUB-ASSEMBLY (See
page FU-13)
4. REMOVE AIR CLEANER FILTER ELEMENT (See page
EM-28)
5. REMOVE AIR CLEANER CASE SUB-ASSEMBLY (See
page EM-28)
6. REMOVE AIR CLEANER BRACKET
(a ...
