Toyota Sienna Service Manual: 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 from the engine room relay block.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance 
2 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 
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
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 moto ...
Back-up Power Source Circuit
DESCRIPTION
This is the back-up power source for the A/C amplifier. Power is supplied
even when the ignition switch is
off and is used for diagnostic trouble code memory, etc.
WIRING DIAGRAM
...
Other materials:
Diagnosis system
1. CHECK DLC3
(a) The vehicle's ECM uses the ISO 15765-4 for
communication. The terminal arrangement of the
DLC3 complies with SAE J1962 and matches the
ISO 15765-4 format.
HINT:
Connect the cable of the intelligent tester to the
DLC3, turn the ignition switch to the ON position
and atte ...
Heated steering
wheel/seat heaters
Heated steering wheel and seat heaters heat the side grips of the
steering wheel and seats, respectively.
WARNING
Care should be taken to prevent injury if anyone in the
following categories
comes in contact with the steering wheel and seats when the heater
is on:
...
Passenger Side Buckle Switch Circuit Malfunction
DTC B1771 Passenger Side Buckle Switch Circuit Malfunction
DESCRIPTION
The passenger side buckle switch circuit consists of the occupant
classification ECU and the front seat
inner belt assembly RH.
DTC B1771 is recorded when a malfunction is detected in the passenger side
buckle switch ci ...
