Toyota Tundra. Manual — part 170

Fig. 99: Identifying K4 And K15 Connectors Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

A: REPAIR OR REPLACE HARNESS OR CONNECTOR

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

a. Disconnect the K4 receiver connector.

b. Measure the resistance according to the value(s) in the table below.

Standard resistance

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Audio/Visual - Tundra

TESTER CONNECTION SPECIFIED CONDITION

Result:

RESULT REFERENCE

B: REPLACE RADIO RECEIVER (see REMOVAL )

Fig. 100: Identifying Radio Receiver Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

C: REPLACE RADIO RECEIVER (see REMOVAL )

A: Go to Next Step

2. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER - COMPONENT WHICH HAS

STORED THIS CODE)

HINT:

For details of the connectors, refer to the "TERMINALS OF ECU" .

a. Referring to the AVC-LAN wiring diagram below, check all AVC-LAN circuits.

1. Disconnect all connectors in all AVC-LAN circuits.

2. Check for an open or short in all AVC-LAN circuits.

OK: There is no open or short circuit.

Tester Connection

Condition Specified Condition

K4-5(ATX+) - K4-15 (ATX-) Always

60 to 80 ohms

Result

Proceed to

OK

A

NG (for Column Shift Type)

B

NG (for Floor Shift Type)

C

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Audio/Visual - Tundra

Fig. 101: AVC-LAN Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE (see PROBLEM SYMPTOMS TABLE )

VEHICLE SPEED SIGNAL CIRCUIT BETWEEN STEREO COMPONENT AMPLIFIER AND
COMBINATION METER

DESCRIPTION

This circuit is necessary for the ASL (Auto Sound Leveliser) built into the stereo component amplifier.

Speed signals are received from the combination meter and used for the ASL.

The ASL function automatically adjusts the sound data in order to enable the driver to hear clear audio sound
even when vehicle noise increases (as vehicle noise increases, the volume is turned up, etc.).

HINT:



A voltage of 12 V or 5 V is output from each ECU and then input to the combination meter. The signal is
changed to a pulse signal at the transistor in the combination meter. Each ECU controls the respective
system based on the pulse signal.



If a short occurs in an ECU, all systems in the diagram below will not operate normally.

WIRING DIAGRAM

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Audio/Visual - Tundra

Fig. 102: Vehicle Speed Signal Circuit Between Stereo Component Amplifier And Combination Meter -
Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

1. CHECK OPERATION OF SPEEDOMETER

a. Drive the vehicle and check if the function of the speedometer on the combination meter is normal.

OK: Actual vehicle speed and the speed indicated on the speedometer are the same.

HINT:



The vehicle speed sensor is functioning normally when the indication on the speedometer is
normal.



The speed indicated on the speedometer has an allowable margin of error. This can be tested
using a speedometer tester (calibrated chassis dynamometer). For details about testing and
the margin of error, refer to "OPERATION CHECK" in the meter/gauge system (see
OPERATION CHECK ).

NG: Go TO METER / GAUGE SYSTEM (See OPERATION CHECK )

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Audio/Visual - Tundra