Vehicle Speed Signal Circuit between Navigation ECU and Combination Meter [06/2018 - 03/2019]: Description

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2023 Toyota GR Corolla, 2023 Toyota Corolla, 2022 Toyota Corolla, 2021 Toyota Corolla, and 2020 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.

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.