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:
Disassembly
1. REMOVE NO. 1ULTRASONIC SENSOR RETAINER
(w/ Clearance Sonar System) (See page PM-19)
2. REMOVE NO. 1 ULTRASONIC SENSOR (w/
Clearance Sonar System) (See page PM-19)
3. REMOVE REAR BUMPER ENERGY ABSORBER
4. REMOVE REAR BUMPER BAR PLATE
Remove the 4 clips and the rear bumper bar plate.
5. ...
Error in Picture Circuit/ No Current in Back-light/ Excess Current in
Back-light
DTC 34-10 Error in Picture Circuit
DTC 34-11 No Current in Back-light
DTC 34-12 Excess Current in Back-light
DESCRIPTION
DTC No.
DTC Detection Condition
Trouble Area
34-10
Error in power supply system for picture circuit
Radio and navigation assembly
...
Front Fog Light Circuit
DESCRIPTION
The Multiplex network body ECU controls FOG relay when signal is received
from headlight dimmer
switch assembly.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 PERFORM ACTIVE TEST BY INTELLIGENT TESTER
Connect the intelligent tester to DLC3.
Turn the ignition switch ON and push t ...
