Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001BTCY
Model Year Start: 2019 Model: Avalon HV Prod Date Range: [04/2018 -           ]
Title: NAVIGATION / MULTI INFO DISPLAY: NAVIGATION SYSTEM (for HV Model): Vehicle Speed Signal Circuit between Navigation ECU and Combination Meter; 2019 - 2022 MY Avalon HV [04/2018 -        ]

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 power 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)
NG

GO TO METER / GAUGE SYSTEM 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; METER / GAUGE / DISPLAY: METER / GAUGE SYSTEM (for HV Model): Speed Signal Circuit 2021 - 2022 MY Avalon HV [08/2020 -        ]; METER / GAUGE / DISPLAY: METER / GAUGE SYSTEM (for HV Model): Speed Signal Circuit

OK

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.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

G13-9 (SPD) - G16-6 (+S)

Always

Below 1 Ω
OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; NAVIGATION / MULTI INFO DISPLAY: NAVIGATION SYSTEM (for HV Model): PROBLEM SYMPTOMS TABLE 2021 - 2022 MY Avalon HV [08/2020 -        ]; NAVIGATION / MULTI INFO DISPLAY: NAVIGATION SYSTEM (for HV Model): PROBLEM SYMPTOMS TABLE

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR