Maintaining your 2013 Subaru Forester is crucial for its longevity and performance. One essential aspect of modern car maintenance involves utilizing the On-Board Diagnostics II (OBD2) system. This system allows mechanics and car owners to access valuable information about the vehicle’s health and diagnose potential issues. A common task that might require accessing the OBD2 port is when you need to disconnect the car battery while preserving important computer settings. While disconnecting the battery is sometimes necessary, it can lead to the loss of radio presets, clock settings, and even impact the engine’s learned parameters. Fortunately, by understanding the OBD2 system and its location in your 2013 Subaru Forester, you can navigate these situations more effectively.
Many car owners and even some service technicians are unaware that disconnecting the battery can erase learned data from various control modules in your Subaru. This data is vital for optimizing your car’s performance. Furthermore, simple conveniences like your saved radio stations and clock settings will also be lost. In some vehicles, the accessory power outlet remains active even when the ignition is off, offering a way to maintain power while changing the battery. However, this is not the case with Subaru Foresters, including the 2013 model. Their accessory outlets are not constantly powered.
So, where can you find a constant power source to prevent memory loss in your 2013 Subaru Forester when disconnecting the battery? The answer lies in the OBD2 connector. Specifically, pin 16 of the OBD2 port is designed to be always connected to the vehicle’s electrical system. This makes it a potential point to introduce temporary power.
Many professional service centers utilize specialized adapters to connect a 12V power source, such as a jump starter, directly through the OBD2 connector. This method, often used with a 7.5 Amp fuse for safety, can effectively maintain power to the car’s computer systems while the battery is disconnected.
However, it’s crucial to exercise caution when using this method. While the power draw from the car’s modules to retain memory is minimal, activating any other electrical component can easily overload the circuit. For instance, simply opening a door and turning on the interior lights can draw a significant amount of current. If this current draw exceeds the 7.5 Amp fuse rating while the car battery is removed, the fuse will blow. The consequence of a blown fuse in this scenario is the same as if you hadn’t used a power maintainer at all – you’ll lose your presets and the car’s computer might need to relearn some parameters, potentially leading to a rough idle for a short period after reconnecting the battery.
This situation – accidentally blowing the fuse while trying to maintain power – is quite common. You’ll often notice it by the reset clock and radio, and potentially a temporary rough idle as the engine control module (ECM) readjusts. It’s plausible that a technician replacing your battery might have attempted to use the OBD2 port for power, but inadvertently activated another electrical system, causing the fuse to blow.
It’s important to note that this fuse, typically associated with the OBD2 power supply, is not related to the Check Engine Light (CEL). A blown fuse will not trigger a CEL. However, if this fuse is blown, it will prevent a code reader that relies on the car’s power from operating correctly when connected to the OBD2 port. Therefore, if you are trying to read diagnostic codes and your reader is not powering up, checking this fuse would be a wise first step.
In conclusion, the OBD2 port in your 2013 Subaru Forester, specifically pin 16, can be used as a point to supply temporary power during battery disconnection to preserve crucial settings. However, it’s vital to proceed with caution and ensure no other electrical systems are activated to avoid blowing the protective 7.5 Amp fuse. Understanding this location and procedure can save you from the minor inconveniences of lost settings and potential temporary performance issues after a battery replacement.
