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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Display check mode
HINT:
This mode checks the color display on the display.
Illustrations may differ from the actual vehicle depending
on the device settings and options. Therefore, some
detailed areas may not be shown exactly the same as on
the actual vehicle.
1. ENTER DIAGNOSTIC MODE
2. D ...
On-vehicle inspection
1. INSPECT FUEL CUT RPM
(a) Increase the engine speed to at least 3500 rpm.
(b) Use a sound scope to check for injector operating
sounds.
(c) Check that when the throttle lever is released,
injector operating sounds stop momentarily (at 2500
rpm) and then resume (at 1400 rpm).
Standard
...
Diagnosis Circuit
DESCRIPTION
DTC output mode is set by connecting terminals TC and CG of the DLC3.
DTCs are displayed by blinking the SRS warning light.
HINT:
When each warning light stays blinking, a ground short in the
wiring of terminal TC of the DLC3 or an
internal ground short in each ECU is ...
