Toyota Avalon Service & Repair Manual: Vehicle Speed Signal Circuit between Navigation ECU and Combination Meter

Toyota Avalon Service & Repair Manual / Audio, Visual, Telematics / Navigation / Multi Info Display / Navigation System(for Gasoline Model) / Vehicle Speed Signal Circuit between Navigation ECU and Combination Meter

DESCRIPTION

The navigation ECU receives a vehicle speed signal from the combination meter assembly.

HINT:

A voltage of 12 V or 5 V is output from each ECU and then input to the combination meter assembly. The signal is changed to a pulse signal at the transistor in the combination meter assembly. Each ECU controls its respective systems based on this pulse signal.
If a short occurs in any of the ECUs or in the wire harness connected to an ECU, all systems in the following diagram will not operate normally.

WIRING DIAGRAM

PROCEDURE

1.	CHECK COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)

(a) Check the output waveform.

(1) Remove the combination meter assembly with the connector(s) still connected.

(2) Connect an oscilloscope to terminal G16-6 (+S) and body ground.

(3) Turn the engine switch on (IG).

(4) Turn a wheel slowly.

(5) Check the signal waveform according to the condition(s) in the table below.

Item	Condition
Measurement terminal	G16-6 (+S) - Body ground
Tool setting	5 V/DIV., 20 ms./DIV.
Vehicle condition	Wheel being rotated

OK:

The waveform is similar to that shown in the illustration.

HINT:

When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.

*a	Component with harness connected (Combination Meter Assembly)

GO TO METER / GAUGE SYSTEM

2.	CHECK HARNESS AND CONNECTOR (NAVIGATION ECU - COMBINATION METER ASSEMBLY)

(a) Disconnect the G13 navigation ECU connector.

(b) Disconnect the G16 combination meter assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
G13-9 (SPD) - G16-6 (+S)	Always	Below 1 Ω

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

REPAIR OR REPLACE HARNESS OR CONNECTOR

USB Audio System Recognition/Play Error

Vehicle Speed Signal Circuit between Stereo Component Amplifier and Combination Meter

See More:

Toyota Avalon Owners Manual > Before driving: Vehicle load limits
Vehicle load limits include total load capacity, seating capacity, towing capacity and cargo capacity. Total load capacity (vehicle capacity weight): Total load capacity means the combined weight of occupants, cargo and luggage. Seating capacity: 5 occupants (Front 2, Rear 3) Seating capacity means ...