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 FRONT DOOR LOWER FRAME BRACKET GARNISH
2. REMOVE FRONT DOOR INSIDE HANDLE BEZEL PLUG
3. REMOVE FRONT DOOR ARMREST BASE PANEL
ASSEMBLY
4. REMOVE BACK FRAME PLATE
5. REMOVE POWER WINDOW REGULATOR MASTER SWITCH ASSEMBLY
6. REMOVE FRONT DOOR TRIM BOARD SUBASSEMBLY
7. REMOVE OUTER RE ...
Adjustment
1. VEHICLE PREPARATION FOR HEADLIGHT AIMING
ADJUSTMENT
Prepare the vehicle:
Ensure there is no damage or deformation to the
body around the headlights.
Fill the fuel tank.
Make sure that the oil is filled to the specified
level.
Make sure that the c ...
Removal
HINT:
Remove the RH side by same procedures with LH side.
1. REMOVE FRONT WHEEL
2. REMOVE FRONT FENDER LINER LH
3. REMOVE FRONT SPEED SENSOR LH
(a) Disconnect the speed sensor connector.
(b) Remove the sensor harness and clamp from the
body.
(c) Remove the 2 clamp bolts holding the ...
