Vehicle Speed Signal Circuit Between Navigation ECU and Combination Meter: Description

WARNING: This page is about a different car, the 2008 Lexus RX 350. 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 and information about the GPS antenna, and then adjusts vehicle position.

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.