Often confused, the slow down light is different to a check engine light.
The slow down light system specifically relates only to detection of overheated exhaust gasses via a temperature monitor within the catalytic converter. While the warning is often a false alarm caused by failed electrical parts, a genuine warning can indicate a fire risk.
A check engine light can be cause by many different things and the only way to understand what it means is to plug a scan tool into the OBD port under the dashboard. A check engine light is usually caused by errors detected in the engine management system and associated controllers (transmission, airbags, suspension).