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:
USE SIMULATION METHOD TO CHECK
DTC B0113/42 Short to B+ in Side Squib RH Circuit
DESCRIPTION
The side squib RH circuit consists of the center airbag sensor assembly and
the front seat side airbag
assembly RH.
This circuit instructs the SRS to deploy when deployment conditions are met.
DTC B0113/42 is recorded when a sh ...
Short to B+ in Curtain Shield Squib LH Circuit
DTC B1168/86 Short to B+ in Curtain Shield Squib LH Circuit
DESCRIPTION
The curtain shield squib LH circuit consists of the center airbag sensor
assembly and the curtain shield
airbag assembly LH.
The circuit instructs the SRS to deploy when deployment conditions are met.
DTC B1168/86 is ...
Brake
GENERAL MAINTENANCE
1. INSPECT BRAKE LINE PIPES AND HOSES
HINT:
Check the entire circumference and length of the brake
hoses using a mirror as required in a well-lighted area.
Turn the front wheels fully right or left before checking
the front brakes.
(a) Check all the brake lines and h ...
