Monitor Description

The ECM monitors the pressure in the secondary air passage using the pressure sensor located on the air switching valve of the secondary air injection system. The sensor detects the exhaust pressure in the secondary air passage.

If either of the following conditions occurs, the ECM interprets it as a malfunction of the secondary air injection system, and illuminates the MIL and sets a DTC:

• The pulsation signal is transmitted by the pressure sensor despite the ECM signaling the Vacuum Switching Valve (VSV) to close the air switching valve.
• The pulsation signal is not transmitted by the sensor despite the ECM signaling the VSV to open the air switching valve.