The camshaft timing gear assembly contained advance and retard oil passages, as well as a detent oil passage to make intermediate locking possible.
As a result, the hydraulically-controlled camshaft could not respond to ECU signals.
Furthermore, the electronically controlled throttle regulated idle speed, traction control, stability control and cruise control functions.
When the engine was stopped, the spool valve was put into an intermediate locking position on the intake side by spring power, and maximum advance state on the exhaust side, to prepare for the next activation.
The FA20D engine was introduced in the and ; for the latter, Toyota initially referred to it as the 4U-GSE before adopting the FA20 name.
The mass air flow meter also had a built-in intake air temperature sensor.