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:
DVD Player Mechanical Error/ DVD Insertion and Ejection Error/ DVD Reading
Abnormal
DTC 44-10 DVD Player Mechanical Error
DTC 44-11 DVD Insertion and Ejection Error
DTC 44-12 DVD Reading Abnormal
DESCRIPTION
TC No.
DTC Detection Condition
Trouble Area
44-10
A mechanical error in the DVD player is detected while
the DVD is not being insert ...
Front Airbag Sensor LH Circuit Malfunction
DTC B1149/37 Front Airbag Sensor LH Circuit Malfunction
DESCRIPTION
The front airbag sensor LH circuit consists of the center airbag sensor
assembly and front airbag sensor
LH.
If the center airbag sensor assembly receives signals from the front airbag
sensor LH, it judges whether or
not ...
On-vehicle inspection
1. INSPECT FRONT AIRBAG SENSOR (VEHICLE NOT
INVOLVED IN COLLISION)
Perform a diagnostic system check.
2. INSPECT FRONT AIRBAG SENSOR (VEHICLE
INVOLVED IN COLLISION AND AIRBAG HAS NOT
DEPLOYED)
Perform a diagnostic system check.
When the front bumper of the vehicle o ...
