System Description/Monitoring Procedure
WARNING: This page is about a different car, the 2010 Suzuki Kizashi. However, it is still accessible from the selected car via links, so may be relevant.
The ECM retards the ignition timing and increases the idle air to quickly increase the catalyst temperature at cold start to reduce emissions. The ECM monitors the ignition timing and the idle air for cold starts. If the idle air or the ignition timing is out of specification, the ECM will set DTC.