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 ...
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Check mode procedure
1. CHECK MODE (SIGNAL CHECK): DTC CHECK
Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Select the "SIGNAL CHECK", and proceed
checking using the intelligent tester.
NOTICE:
Select the "SIGNAL CHECK" from the ...
Passenger Airbag ON/OFF Indicator Circuit
Malfunction
DTC B1152/28 Passenger Airbag ON/OFF Indicator Circuit
Malfunction
DESCRIPTION
The passenger airbag ON/OFF indicator circuit consists of the center airbag
sensor assembly and
passenger airbag ON/OFF indicator.
This circuit indicates the operation condition of the front passenger airbag,
t ...
Engine Coolant Temperature Circuit Range / Performance Problem
DESCRIPTION
Refer to DTC P0115 (See page ES-133).
MONITOR DESCRIPTION
The ECT sensor is used to monitor the ECT. The ECT sensor has a built-in
thermistor with a resistance
that varies according to the temperature of the engine coolant. When the ECT
becomes low, the
resistance of the ...
