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:
ABS Control System Malfunction
DTC 43 ABS Control System Malfunction
DESCRIPTION
This DTC is output when the VSC system detects a malfunction in the ABS
control system.
INSPECTION PROCEDURE
NOTICE:
When replacing the brake actuator assembly, perform zero point calibration
(See page BC-70).
1 CHECK ABS CONTROL SYSTEM
( ...
Replacement
1. DISCHARGE REFRIGERANT FROM
REFRIGERATION SYSTEM
SST 07110-58060 (07117-58080, 07117-58090,
07117-78050, 07117-88060, 07117-88070,
07117-88080)
(a) Turn the A/C switch to ON.
(b) Operating the cooler compressor at the engine rpm
of approx. 1,000 for 5 to 6 minutes, circulate the
refriger ...
Diagnostic trouble code chart
HINT:
If a trouble code is displayed during the DTC check, inspect
the circuit listed for that code. For details of each code, refer
to the relevant page listed under respective "DTC No." in the
DTC chart.
TIRE PRESSURE WARNING SYSTEM:
...
