Maintaining your 2020 Subaru Outback in top condition sometimes involves tasks like battery replacement. When disconnecting the battery, you might worry about losing important settings like radio presets and computer memory. Fortunately, your vehicle’s OBD2 port can be a helpful tool in preventing data loss during this process. Let’s explore the location of the OBD2 port in your 2020 Subaru Outback and how it can be utilized during a battery change.
Finding the OBD2 Port in Your 2020 Subaru Outback
The OBD2 (On-Board Diagnostics II) port is a standardized connector in your car used for diagnostics and accessing vehicle data. In the 2020 Subaru Outback, you’ll typically find the OBD2 port located inside the cabin on the driver’s side. Look under the dashboard, usually near the steering column. It’s often situated in the area above your pedals, easily accessible for mechanics and car owners alike. The port is usually trapezoidal in shape with 16 pins.
Understanding the OBD2 Port and Constant Power
One key feature of the OBD2 port, specifically pin 16, is that it’s designed to provide constant power. This means it remains powered even when the car is turned off. This constant power supply is intended for diagnostic tools that need power to operate and communicate with the vehicle’s computer systems. Unlike accessory power outlets in some vehicles which may be switched, the OBD2 port’s pin 16 offers a direct connection to the battery.
This constant power feature becomes relevant when you need to disconnect your car battery. Disconnecting the battery can lead to a loss of learned data in control modules, radio presets, and clock settings. While some vehicles allow using the accessory outlet to maintain power during a battery change, Subaru Outbacks typically don’t have constantly powered accessory outlets. This is where the OBD2 port comes into play as an alternative power source.
Utilizing the OBD2 Port for Battery Replacement: A Safe Approach
Technicians often use the OBD2 port to connect a 12V power source, like a jump starter or battery maintainer, when replacing a car battery. By connecting a power supply to pin 16 of the OBD2 port, you can maintain power to the car’s electrical system while the main battery is disconnected. This prevents the loss of those valuable memory settings.
However, it’s crucial to exercise caution. These systems often incorporate a fuse, typically around 7.5 Amps, in the circuit to protect the vehicle’s electronics. This fuse is sufficient for maintaining the memory of the modules, which requires minimal current. The problem arises when additional electrical loads are introduced.
A common mistake is inadvertently turning on accessories like interior lights by opening a door during the battery replacement process. Even seemingly small loads can draw significant current. If the total current draw exceeds the 7.5 Amp fuse rating while the car battery is disconnected, the fuse will blow. When this fuse blows, it defeats the purpose of using the OBD2 port for power, and you’ll experience the same memory loss as if you hadn’t used it at all.
Consequences of Fuse Overload and Best Practices
If the fuse protecting the OBD2 power circuit blows, you’ll likely notice the same symptoms as if you had simply disconnected the battery without any power maintenance. Your radio presets will be gone, the clock will need resetting, and the engine control module (ECM) might need to relearn its optimal settings, potentially causing a slightly rougher idle for a short period after the battery replacement.
It’s important to note that a blown fuse in this circuit will not trigger a Check Engine Light (CEL). However, if you attempt to use an OBD2 code reader after blowing this fuse and the reader relies on vehicle power, it may not function because it’s not receiving power through the blown fuse.
To successfully use the OBD2 port for battery replacement and avoid issues:
- Ensure all vehicle accessories, including lights, are turned off before disconnecting the battery.
- Keep doors closed during the battery replacement process to prevent interior lights from activating.
- Use a reliable 12V power source and connect it carefully to the OBD2 port using an appropriate adapter.
- Work efficiently to minimize the time the battery is disconnected.
By understanding the location and power capabilities of your 2020 Subaru Outback’s OBD2 port, you can approach battery replacement with more confidence and avoid the frustration of lost settings. However, always proceed with caution and consult a professional mechanic if you are unsure about any step of the process.
