Maintaining your Subaru WRX in top condition often involves routine maintenance, and sometimes, that includes disconnecting the car battery. Whether you’re performing a battery replacement or working on electrical components, disconnecting the power source can lead to a frustrating issue: the loss of your car’s learned settings. This article will guide you on how to prevent this by utilizing the OBD2 port in your 2015 WRX, specifically focusing on its location and how to use it to maintain power during battery changes.
Understanding the inconvenience of losing radio presets, clock settings, and even engine management memory after a battery disconnect is key. Modern vehicles, including the 2015 Subaru WRX, rely on constant power to retain these settings in their various control modules. Fortunately, your WRX, like most modern cars, is equipped with an On-Board Diagnostics II (OBD2) port. This port isn’t just for diagnostics; it can also be a handy point to supply temporary power.
Pin 16 of the OBD2 connector is designed to be always hot, meaning it’s constantly connected to the car’s electrical system, even when the ignition is off. This makes it a potential access point for feeding power to the car’s system while the main battery is disconnected. For your 2015 WRX, the OBD2 port is typically located under the dashboard on the driver’s side. You’ll usually find it near the steering column or around the foot pedal area. It’s a 16-pin trapezoidal connector, easily identifiable once you know where to look.
Alt text: The OBD2 port location in a 2015 Subaru WRX, positioned under the driver’s side dashboard, near the steering column, for accessing vehicle diagnostics and maintaining power during battery replacement.
To use the OBD2 port to maintain power during a battery change on your 2015 WRX, you’ll need a 12V power source and an OBD2 connector adapter. Many automotive service centers use specialized tools for this, but you can also achieve this with a portable jump starter or another 12V battery and a compatible adapter. The process involves connecting your 12V source to pin 16 of the OBD2 port before disconnecting the main car battery. This ensures a continuous power supply to the vehicle’s systems, preserving those crucial settings.
However, it’s crucial to proceed with caution. The OBD2 port circuit is usually protected by a fuse, often a 7.5 Amp fuse. This fuse is designed to protect the system from overloads. While the power draw from the car’s modules to maintain memory is minimal, accidentally turning on accessories like interior lights or the radio can drastically increase the current draw. If this draw exceeds 7.5 Amps while the car battery is disconnected and you’re powering through the OBD2 port, you’ll likely blow this fuse.
Blowing this fuse defeats the purpose, resulting in the same issue as if you hadn’t maintained power at all – loss of settings. It’s a common mistake, even for experienced technicians, to inadvertently trigger something that increases the power demand during this process. The telltale signs are the reset clock and radio, and potentially a slightly rough idle immediately after reconnecting the battery as the engine control module (ECM) relearns its parameters.
Therefore, when using the OBD2 port in your 2015 WRX to maintain power during battery replacement, ensure absolutely nothing in the car is turned on. Double-check that headlights, interior lights, radio, and any other accessories are switched off before disconnecting the battery. By understanding the location of your 2015 WRX’s OBD2 port and following these precautions, you can seamlessly replace your car battery without losing your preferred settings and configurations, making the maintenance process smoother and less frustrating.
