Toyota Sienna Service Manual: 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
INSPECTION PROCEDURE
1 INSPECT FUSE (ECU-B)
(a) Remove the ECU-B fuse from the engine room junction 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
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:
ECM Power Source Circuit
DESCRIPTION
When the ignition switch is turned to the ON position, the battery voltage is
applied to terminal IGSW of
the ECM. The ECM MREL output signal causes a current to flow to the coil,
closing the contacts of the EFI
relay and supplying power to terminal +B of the ECM.
If the igniti ...
On-vehicle inspection
1. INSPECT SIDE AIRBAG SENSOR (VEHICLE NOT
INVOLVED IN COLLISION)
Perform a diagnostic system check.
2. INSPECT SIDE AIRBAG SENSOR (VEHICLE
INVOLVED IN COLLISION AND AIRBAG HAS NOT
DEPLOYED)
Perform a diagnostic system check.
When the center pillar of the vehicle or its a ...
System description
1. GENERAL
This system uses ultrasonic sensors to detect any
obstacles at the corners and the rear of the vehicle.
The system then informs the driver of the distance
between the sensors and the obstacles as well as
their positions by indicating them on the clearance
sonar displ ...
