Toyota Sienna Service Manual: AVC-LAN Circuit
DESCRIPTION
Each unit of the audio system connected to the AVC-LAN (communication bus) transfers the signal of each switch by communication.
When a short to +B or short to ground occurs in this AVC-LAN, the audio system will not function normally as the communication is discontinued.
INSPECTION PROCEDURE
1 INSPECT RADIO RECEIVER
- Disconnect the radio receiver connectors.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
*1: 10 Speaker System
2 CHECK HARNESS AND CONNECTOR
HINT: For details of the connectors, refer to the "TERMINALS OF ECU"
- Referring to the AVC-LAN wiring diagram below, check all AVC-LAN circuits.
- Disconnect all connectors in all AVC-LAN circuits.
- Check for an open or short in all AVC-LAN circuits.
OK: There is no open or short circuit
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
Mute Signal Circuit between Radio Receiver and Television Display
Assembly
DESCRIPTION
The radio receiver controls the volume according to the MUTE signal from the
television display
assembly.
The MUTE signal is sent to reduce noise and a popping sound generated when ...
Vehicle Speed Signal Circuit between Multi-display and Combination
Meter
DESCRIPTION
This circuit is necessary for the ASL (Auto Sound Leveliser) built into the
radio receiver.
Speed signals are received from the combination meter and used for the ASL.
The ASL fun ...
Other materials:
Air outlet control servo motor (for rear air conditioning system)
ON-VEHICLE INSPECTION
1. INSPECT REAR AIR OUTLET CONTROL SERVO
MOTOR
(a) Inspect servo motor operation.
(1) Connect the positive (+) lead from the battery
to terminal 4 and negative (-) lead to terminal 5,
then check that the arm turns to "FOOT" side
smoothly.
(2) Connect t ...
Sound Signal Circuit between Radio and Navigation Assembly and
Stereo Jack Adapter
DESCRIPTION
The stereo jack adapter sends an external device sound signal to the radio
and navigation assembly
through this circuit.
The sound signal that has been sent is amplified by the stereo component
amplifier and then is sent to the
speakers.
If there is an open or short in the c ...
Combination Meter ECU Communication Stop
DTC B1271 Combination Meter ECU Communication Stop
DESCRIPTION
DTC B1271 is output when communication between the combination meter and the
multiplex network
gateway ECU stops for more than 10 seconds.
DTC No.
DTC Detection Condition
Trouble Area
B1271
...
