P1656 Diagnostic Code on 2001 Toyota Echo: OCV Circuit Explanation and Location

Model: 2001 Toyota Echo Fault Code: P1656 Posted: 2010-09-22 10:43

My 2001 Toyota Echo has the MIL illuminated with diagnostic code P1656, indicating an Open Circuit Voltage (OCV) issue. I'm trying to understand what the OCV sensor looks like and where it's located on the engine. Can anyone provide a clear explanation of this fault code and its physical location for reference?