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:
Circuit opening relay
Inspection
1. INSPECT CIRCUIT OPENING RELAY
Using an ohmmeter, measure the resistance
according to the value(s) in the table below.
Standard resistance
If the result is not as specified, replace the relay. ...
Unmatched Encryption Code
DTC B2794 Unmatched Encryption Code
DESCRIPTION
This DTC is output when a key with an incomplete key code is inserted into
the ignition key cylinder.
DTC No.
DTC Detection Condition
Trouble Area
B2794
Key with incomplete key code inserted
Key
IN ...
Removal
HINT:
Remove the RH side by the same procedure as the LH side.
1. REMOVE FRONT WHEEL
2. DRAIN BRAKE FLUID
NOTICE:
Wash the brake fluid off immediately if it attaches to
any painted surface.
3. REMOVE FRONT DISC BRAKE CYLINDER SUBASSEMBLY
(a) Remove the union bolt and 2 gaskets from the f ...
