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:
Antenna Coil Open / Short
DTC B2784 Antenna Coil Open / Short
DESCRIPTION
The transponder key coil is built into the transponder key amplifier and
receives a key code signal from
the transponder chip in the key. This signal is amplified by the amplifier, and
output to the transponder key
ECU.
DTC No.
...
Window lock switch
Press the switch down to lock the
passenger window switches.
Use this switch to prevent children
from accidentally opening or closing
a passenger window.
The power windows can be operated when
The engine switch is in the “ON” position (vehicles without a smart key
system)
or IGNIT ...
Camshaft Position "A" Actuator Circuit
DTC P0010 Camshaft Position "A" Actuator Circuit (Bank
1)
DTC P0020 Camshaft Position "A" Actuator Circuit (Bank
2)
DESCRIPTION
The Variable Valve Timing (VVT) system includes the ECM, Oil Control Valve (OCV)
and VVT controller.
The ECM sends a target duty-cycle control ...
