Review on 🔌 Fotag OBD2 16 Pin to DB9 RS232 Serial Port Adapter Cable with Power Switch - 1.5M 5ft by Jeremy Hong

This adapter works great. Some reviewers have found that this doesn't work on their PC, which is exactly right: it's not a signal level adapter, just a cable with two different types of connectors on each end. It does not convert signal levels and is not designed to do so. In conjunction with various devices, i2c can read and write to the car's CAN bus. In addition, since the vehicle's CAN port is always powered, the switch is convenient as you can easily turn off the power without draining the battery or disconnecting the cable. The cord is also long enough that I can leave it plugged in and neatly route it to the passenger seat while driving. The contacts are correct in the description of this product.