Variable valve timing. VTEC, VVTI and VANOS — we’ve all heard these terms thrown around by mechanics for decades. Simply put, these systems all adjust the cam timing to improve how your engine functions.
However, we know as car owners that introducing more complexity means more components that can fail. The P0021 is the check engine light code for a failure in this system.
Here you’ll find how to diagnose and fix this trouble code. You’ll also find the most common causes, symptoms and any preventative measures you can take when encountering this issue. So, let’s get into it!