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:
Fold Seat Switch Circuit
DESCRIPTION
When the fold seat switch is operated, a switch operation signal is sent to
the fold seat control ECU. The
ECU receives switch operation signals from each switch and activates the folding
motor, reclining motor,
and release actuator.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 IN ...
Phone screen
To display the screen shown below, press the
switch on the steering
wheel or the button.
Several functions are available to operate on each screen that is displayed
by selecting the 4 tabs.
Device name
Bluetooth® connection status
Telephone switch
Microphone
The vehicleâ ...
Removal
1. Disconnect cable from negative battery
terminal
2. REMOVE HEATED OXYGEN SENSOR (for Bank 1
Sensor 2) (See page EC-32)
3. REMOVE TAIL EXHAUST PIPE ASSEMBLY
(a) Remove the 2 bolts.
(b) Disconnect the 3 exhaust pipe supports and remove
the tail exhaust pipe assembly.
(c) Remove the gas ...
