Modern vehicles, like the 2016 Subaru STI, rely heavily on computer systems that learn and adapt to driving habits and conditions. When you disconnect the battery, these systems can lose their learned settings, along with your radio presets and clock. This article will guide you on how to utilize the OBD2 port in your 2016 STI to prevent memory loss during battery changes or disconnections.
Understanding Memory Loss in Modern Vehicles
Disconnecting your car battery might seem like a simple task, but it can lead to more than just a reset clock. Today’s cars are equipped with various control modules that store data crucial for optimal performance. This “learned” information helps your engine run efficiently, your transmission shift smoothly, and other systems operate correctly. When power is interrupted, these modules can lose this data, potentially leading to temporary issues like rough idling after reconnecting the battery until the car relearns. Beyond engine management, simpler conveniences like your saved radio stations and clock settings are also erased without a constant power supply.
The OBD2 Port Solution for Your 2016 STI
Fortunately, there’s a way to prevent this memory loss in your 2016 Subaru STI. While some vehicles allow you to use the accessory power outlet to maintain power during a battery disconnect, Subarus, including the 2016 STI, typically do not have constantly powered accessory outlets. However, your car’s On-Board Diagnostics II (OBD2) port offers an alternative. Specifically, pin 16 of the OBD2 connector is designed to be always powered, providing a direct connection to the car’s electrical system, even with the battery disconnected.
This constant power supply via the OBD2 port can be utilized to temporarily power the car’s computer systems while you change the battery. By connecting a 12V power source to pin 16 through a specialized adapter, you can effectively keep the memory alive, preserving your settings and learned data.
Locating the OBD2 Port in Your 2016 STI
Before attempting to use the OBD2 port for memory maintenance, you first need to locate it in your 2016 STI. The OBD2 port is standardized and usually found in the driver’s side interior of most vehicles. For the 2016 Subaru STI, you’ll typically find the OBD2 port located under the dashboard on the driver’s side. It’s often near the steering column or in the footwell area. Look for a 16-pin connector, usually trapezoidal in shape. Consult your 2016 Subaru STI owner’s manual for the precise location if you are unsure.
Safe Memory Maintenance via OBD2: Step-by-Step
Maintaining your 2016 STI’s memory through the OBD2 port requires caution and the right equipment. Here’s a step-by-step guide:
- Gather your tools: You will need an OBD2 memory saver adapter, a 12V power source (like a jump starter or another car battery), and potentially a 7.5 Amp fuse as a spare.
- Locate the OBD2 port: As described above, find the OBD2 port in your 2016 STI.
- Connect the memory saver: Plug the OBD2 memory saver adapter into the OBD2 port.
- Connect the 12V power source: Attach the 12V power source to the memory saver adapter, ensuring correct polarity (positive to positive, negative to negative).
- Disconnect the car battery: With the memory saver providing power, you can now safely disconnect your 2016 STI’s battery.
- Perform battery service: Change your battery or perform any necessary work.
- Reconnect the car battery: Once finished, reconnect the car’s battery terminals.
- Disconnect the memory saver: Finally, disconnect the 12V power source and remove the OBD2 memory saver adapter from the OBD2 port.
Important Precautions:
- Fuse Rating: Most OBD2 memory saver circuits are protected by a 7.5 Amp fuse. This is sufficient for maintaining memory but can blow if excessive current is drawn.
- Avoid activating accessories: Ensure all car accessories like lights, radio, and interior fan are turned off during the process. Opening a door and turning on interior lights can draw enough current to blow the 7.5A fuse when the main battery is disconnected.
- Fuse Failure: If the fuse blows during the process, it’s the same as disconnecting the battery without memory maintenance – you will lose your settings. This fuse is not related to check engine lights but will prevent an OBD2 code reader from working if it relies on car power.
Potential Issues and Troubleshooting
The most common issue when using the OBD2 port for memory maintenance is blowing the 7.5 Amp fuse in the memory saver circuit. This typically happens if any electrical accessory in the car is inadvertently turned on while the main battery is disconnected and the OBD2 port is supplying power.
If your clock and radio are reset after a battery change despite using a memory saver, it’s likely the fuse blew. Check the fuse in your memory saver adapter and replace it with a 7.5 Amp fuse if necessary.
Also, remember that if the fuse is blown, an OBD2 code reader that relies on the car’s power might not function correctly until the fuse is replaced and power is restored to pin 16.
Conclusion
Using the OBD2 port is a practical method to prevent memory loss when disconnecting the battery in your 2016 Subaru STI. By understanding the OBD2 port location and following the correct procedure with caution, you can avoid the inconvenience of reset settings and ensure a smoother battery service experience. Remember to always prioritize safety and avoid overloading the circuit to protect your car’s electrical system.
