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:
Speaker Circuit
DESCRIPTION
When the vehicle has a built-in type amplifier, a sound signal is
sent from the radio receiver to the
speakers via the "6 Speaker System" circuit.
When the vehicle has a separate type amplifier, a sound signal
from the radio receiver is amplified by
...
Reverse Signal Circuit
DESCRIPTION
The radio and navigation assembly receives a reverse signal from the
park/neutral position switch.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 INSPECT RADIO AND NAVIGATION ASSEMBLY
Disconnect the radio and navigation assembly connector
R12.
Measure the voltage accor ...
How to proceed with
troubleshooting
HINT:
Use these procedures to troubleshoot the key reminder
warning system.
The intelligent tester should be used in steps 3 and 5.
1 VEHICLE BROUGHT TO WORKSHOP
2 CUSTOMER PROBLEM ANALYSIS
3 INSPECT COMMUNICATION FUNCTION OF MULTIPLEX COMMUNICATION SYSTEM
(BEAN)
Use th ...
