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:
Display check mode
HINT:
This mode checks the color display on the display.
Illustrations may differ from the actual vehicle depending
on the device settings and options. Therefore, some
detailed areas may not be shown exactly the same as on
the actual vehicle.
1. ENTER DIAGNOSTIC MODE
2. D ...
Seat Position Airbag Sensor Circuit Malfunction
DTC B1153/25 Seat Position Airbag Sensor Circuit Malfunction
DESCRIPTION
The seat position airbag sensor circuit consists of the center airbag sensor
assembly and the seat
position airbag sensor.
DTC B1153/25 is recorded when a malfunction is detected in the seat position
airbag sensor cir ...
Data list / active test
1. DATA LIST
HINT:
Using the intelligent tester to read the Data List allows
the values or states of switches, sensors, actuators and
other items to be read without removing any parts. This
non-intrusive inspection can be very useful because
intermittent conditions or signals may be discovered ...
