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:
Position Sensor Circuit
DESCRIPTION
When SET and 1 or 2 are pressed, the position sensor detects the mirror
position and sends the signal to
the outer mirror control ECU. Then when position 1 or 2 is pressed, the outer
mirror control ECU drives
the mirror motor based on the memorized sensor positions.
HINT:
The ...
Reassembly
1. INSTALL UNDERDRIVE PLANETARY RING GEAR
HINT:
Use a torque wrench with a fulcrum length of 160
mm (6.3 in.).
(a) Install a new snap ring to the outer race of the radial
ball bearing rear.
HINT:
When replacing the bearing, also replace the
counter driven gear with a new one.
(b) Us ...
Insufficient Coolant Temperature for Closed Loop Fuel Control
DESCRIPTION
Refer to DTC P0115 (See page ES-133).
MONITOR DESCRIPTION
The resistance of the ECT sensor varies in proportion to the actual ECT. The
ECM supplies a constant
voltage to the sensor and monitors the signal output voltage of the sensor. The
signal voltage output
varies acc ...
