Toyota Tundra. Manual — part 216

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.

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. 229: 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

OK: Go to next step.

2. INSPECT STEREO COMPONENT AMPLIFIER

a. Disconnect the K15 amplifier connector.

b. Measure the voltage.

1. Jack up the drive wheels.

2. Move the shift lever to the neutral position.

3. Turn the ignition switch to the ON position.

Fig. 230: Identifying K15 Amplifier Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

4. Measure the voltage between terminal SPD of the stereo component amplifier and body

ground when the drive wheels are turned slowly.

OK: Voltage pulses as shown in the illustration.

NG: Go to step 3

Fig. 231: Voltage Pulses Pattern
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Audio/Visual - Tundra

OK: REPLACE STEREO COMPONENT AMPLIFIER (see REMOVAL )

3. CHECK HARNESS AND CONNECTOR (COMBINATION METER - STEREO COMPONENT

AMPLIFIER)

a. Disconnect the K15 amplifier connector.

b. Disconnect the J28 meter connector.

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

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

HINT:

If the resistance between terminal SPD and body ground is less than 10 kohms, there may be a
short in a wire harness, connector, or an ECU that is connected to the SPD signal wire.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

Fig. 232: Identifying J28 And K15 Connectors Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Tester Connection

Switch Condition Specified Condition

K15-11 (SPD) - J28-35 (+S)

Always

Below 1 ohms

K15-11 (SPD) - Body ground

10 kohms or higher

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Audio/Visual - Tundra