Vehicle Speed Signal Circuit: Description
WARNING: This page is about a different car, the 2008 Toyota Camry Solara. However, it is still accessible from the selected car via links, so may be relevant.
Vehicle speed signals travel from the skid control ECU to the combination meter to the convertible roof control ECU. When the vehicle speed is over 3.5 km/h (2.2 mph), the roof control ECU stops the motors. The vehicle speed is detected by the skid control ECU, which receives vehicle speed signals from its sensor. The skid control ECU then converts these signals into 4-pulse signals and outputs the signals to the combination meter. The combination meter then converts the signals into more precise, rectangular waveforms using its built-in waveform sharping circuit. Finally, the speed signals are output to the roof control ECU. The roof control ECU determines the vehicle speed based on the frequency of the pulse signals.