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 located on the Air Switching Valve (ASV) of the Secondary Air Injection (AIR) system. The sensor measures the pressure in the secondary air passage and transmits a signal to the ECM.

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:

The pressure indicated by the pressure sensor does not reach threshold levels despite the ECM turning on the air pump.
The pressure indicated by the pressure sensor exceeds threshold levels despite the ECM turning off the air pump.