The OBD2 port in your car is a convenient gateway to access your vehicle’s health data. Many car owners use OBD2 scanners and devices for real-time diagnostics, performance monitoring, or even insurance tracking. A common question arises: is it safe and advisable to keep these devices plugged in while driving?
Generally, yes, you can leave your OBD2 scanner plugged in while driving. The OBD2 port, specifically pin 16, is designed to be permanently powered. This is an international standard across all OBD2 compliant vehicles. Therefore, devices plugged into this port will continuously draw power, even when your car is turned off.
However, while technically possible, there are a few considerations. Firstly, power drain. Even though OBD2 devices are designed to be low power, they do consume electricity. As pointed out by experts in car forums like e46fanatics.com, a permanently connected device will contribute to parasitic battery drain. This might be negligible for daily drivers, perhaps increasing your car’s sleep consumption by a small amount, like from 30mA to 40mA. But, if you infrequently use your car, say once a month, this constant drain could lead to a noticeably shorter battery life and potentially require more frequent charging or jump starts.
Secondly, device functionality and safety. Most generic OBD2 readers and apps are designed to manage their power consumption. They often use voltage sensing – typically looking for voltages below 13.2V – to detect when the car is off and enter a sleep mode, minimizing drain. However, even in sleep mode, they are still drawing a small current as they remain connected and monitor the battery to know when to reactivate. While driving, the alternator is running, and the power draw from a typical OBD2 device is insignificant compared to the charging capacity. From a safety perspective, reputable OBD2 devices are designed to be safe to use while driving and should not interfere with your vehicle’s operation.
In conclusion, while leaving your OBD2 device plugged in while driving is generally safe and won’t immediately cause problems, consider the potential for long-term battery drain, especially if you don’t drive your car regularly. For occasional use, it’s perfectly fine to keep it plugged in. But for vehicles that sit idle for extended periods, unplugging the device might be a prudent measure to preserve battery health.
