Toyota Sienna Service Manual: IG Power Source Circuit
DESCRIPTION
The main power source is supplied to the A/C amplifier when the ignition switch is turned to the ON position.
The power source is used for operating the A/C amplifier and servo motor, etc.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT: Start the engine before inspection. Check the IG1 relay or battery if the engine does not start.
1 INSPECT FUSE (HTR)
(a) Remove the HTR fuse from the driver side junction block.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance 
2 INSPECT A/C AMPLIFIER (IG - GND)
(a) Remove the A/C amplifier with its connectors still connected.
(b) Turn the ignition switch to the ON position.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage 
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
3 CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BATTERY)
(a) Disconnect the connector from the A/C amplifier.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage
4 CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BODY GROUND)
(a) Measure the resistance according to the value(s) in the table below.
Standard resistance 
REPLACE A/C AMPLIFIER
Rear Blower Motor Circuit
DESCRIPTION
Power to the rear blower motor is supplied from the battery via the RR A/C
relay.
The rear blower motor speed level varies between 0 and 31 based on the voltage
difference measured ...
ACC Power Source Circuit
DESCRIPTION
This circuit supplies power to the A/C amplifier and the illumination for the
clock.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 INSPECT FUSE (ECU ACC)
(a) Remove the ECU ACC fuse fr ...
Other materials:
Rear view monitor system precautions
Area displayed on screen
The rear view monitor system
displays an image of the view
from the bumper of the rear
area of the vehicle.
The image on the rear view monitor system can be adjusted.
The area displayed on the
screen may vary according to
vehicle orientation conditions.
...
How to proceed with
troubleshooting
HINT:
The intelligent tester can be used in steps 2, 3, 4, 6 and 9.
1 VEHICLE BROUGHT TO WORKSHOP
2 CONNECT INTELLIGENT TESTER TO DLC3
HINT:
If the display indicates a communication fault in the tester,
inspect the DLC3.
3 CHECK DTC AND FREEZE FRAME DATA
(a) Check for DTC(s) and freeze f ...
Differential
SST
RECOMMENDED TOOLS
EQUIPMENT
LUBRICANT
SSM
...
