The On-Board Diagnostics II (OBD2) port in your vehicle is not just for mechanics to diagnose issues. It’s a versatile interface that can also provide power and data for various aftermarket devices, including dashcams. A common question for those installing dashcams is how to obtain ignition-switched power, meaning power that is only active when the car’s ignition is on. While there isn’t a dedicated “Obd2 Ignition Pin” in the traditional sense, OBD-II power cables cleverly utilize the port to detect the vehicle’s ignition status and provide Accessory (ACC) power.
Many modern dashcams offer parking mode, which requires a constant power supply and an ignition signal to switch between continuous recording and parking surveillance. Directly wiring a dashcam to the car’s battery for constant power is possible, but it can lead to battery drain if not managed properly. This is where OBD-II power cables, like the Thinkware TOC-300, come into play, offering a more elegant and user-friendly solution.
These cables draw power from the OBD2 port and, more importantly, intelligently detect when the car’s ignition is on or off. The Thinkware TOC-300, as observed in practical use, demonstrates this functionality effectively. Even with a fully charged car battery showing a voltage between 12.3V and 12.5V during driving, the TOC-300 continues to supply ACC power to the connected dashcam, ensuring continuous recording while the engine is running.
When the vehicle is parked and the car’s systems enter sleep mode, the TOC-300 intelligently cuts off ACC power to the dashcam. This prevents battery drain while still allowing the dashcam to enter parking mode, typically triggered by motion or impact detection, depending on the dashcam’s features and settings. The TOC-300’s ability to stop power delivery after the instrument panel “goes to sleep” indicates a sophisticated monitoring system, likely within the cable itself, that goes beyond simply drawing constant power.
Further observation reveals that the TOC-300 can also restore ACC power when a door is opened, even after the car has been parked and the system has gone to sleep. Opening the driver’s side door, for example, can “wake up” the vehicle’s systems, and the TOC-300 promptly recognizes this change, re-establishing power to the dashcam and switching it back to continuous recording mode. This seamless transition ensures that recording resumes quickly when the driver returns to the vehicle.
The key to the TOC-300’s intelligent behavior likely lies in its monitoring of the Controller Area Network (CANBUS) within the OBD-II port. While the OBD-II port provides several pins for different functions, pins 6 and 14 are standard for CAN high and CAN low, respectively. Modern vehicles heavily rely on CANBUS for communication between various electronic control units (ECUs). It is highly probable that the TOC-300 monitors CANBUS activity on these pins to detect changes in the vehicle’s operational state, including ignition status and door opening events.
While this testing was conducted on vehicles with CANBUS networks, it’s important to note that older vehicles might utilize different communication protocols, such as SAE J1850 VPW, which was found on pin 2 in some older GM vehicles. The compatibility of OBD-II power cables like the TOC-300 with these older protocols may vary and would require further investigation.
In conclusion, while there isn’t a specific “obd2 ignition pin,” OBD-II power cables like the Thinkware TOC-300 offer a convenient and intelligent way to obtain ignition-switched power for dashcams and potentially other vehicle accessories. By leveraging the OBD-II port and likely monitoring CANBUS activity, these cables provide a user-friendly solution for seamless dashcam integration without the complexities of traditional hardwiring to the vehicle’s electrical system.
