Monitor Description

WARNING: This page is about a different car, the 2018 Toyota Sequoia, 2017 Toyota Sequoia, and 2016 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.

The ECM monitors the pressure in the secondary air passage using the pressure sensor connected to the ASV of the Secondary Air Injection (AIR) system.

If either of the following conditions occurs, the ECM interprets it as a malfunction of the AIR system, and illuminates the MIL and stores a DTC:

Exhaust gas pulsation is detected by the pressure sensor despite the ECM commanding the ASV to close.
Exhaust gas pulsation is not detected by the pressure sensor despite the ECM commanding the ASV to open.