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.
For a short time after cold engine starts, the ECM transmits command signals to the Air Injection Control Driver (AID) to drive the air pump and the Air Switching Valve (ASV). The AID detects open and short circuits according to the voltages at the AID terminals to the air pump and ASV, and the circuit voltage of the AID power source, and transmits diagnostic information as a signal to the ECM.
If the Secondary Air Injection (AIR) system circuit or the AID itself malfunctions, the AID sends a malfunction signal (duty signal) as diagnostic information to the ECM (when the system is normal, a system normal signal is sent). The ECM sets the DTC based on the diagnostic information from the AID.
EXAMPLE:
- The duty ratio of the diagnostic signal from the AID is 0 or 100% (remains at 0 V or the same as battery voltage).
- The duty ratio of the diagnostic signal from the AID shows an impossible ratio (other than 0, 20, 40, 80 and 100%).
- The AID outputs the normal signal (normal duty signal: 80%) while the system is not operating.