Vehicle Speed Signal Circuit between Navigation ECU and Multi-Display: Description

WARNING: This page is about a different car, the 2006 Lexus IS 350 and 2006 Lexus IS 250. 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 multi-display 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.