Modern vehicles, including the sporty 2015 Subaru WRX, rely heavily on computer systems to manage everything from engine performance to your radio presets. When you disconnect the battery, many of these systems lose their learned settings, leading to inconveniences like reset clocks, lost radio stations, and even temporary rough idling as the engine control module (ECM) relearns optimal parameters. For 2015 WRX owners, understanding the OBD2 port location is key to preventing this memory loss during battery replacements or disconnections.
Why Maintaining Power Matters When Disconnecting Your Car Battery
Disconnecting your car battery cuts off power to various control modules. These modules store learned data essential for your car’s smooth operation. Think of it like your computer losing its RAM when powered off – temporary settings and configurations are wiped clean. In a car, this can affect:
- Radio Presets and Clock: The most immediately noticeable loss.
- ECM Learned Values: Engine performance parameters optimized over time for your specific driving style and environment. Resetting these can cause temporary issues until the ECM relearns.
- Transmission Control Module (TCM) Settings: Similar to the ECM, the TCM learns shift patterns for optimal gear changes.
- Other Convenience Features: Depending on the car, this could include seat memory positions, climate control settings, and more.
The OBD2 Port: A Power Source for Memory Preservation
Fortunately, there’s a way to supply temporary power to your 2015 WRX’s electrical system while the main battery is disconnected. The On-Board Diagnostics II (OBD2) port, typically used for reading diagnostic trouble codes, has a pin that is constantly powered directly from the battery. This is pin 16.
By carefully connecting a 12V power source to this pin, you can maintain power to the car’s computer systems, preserving their memory and settings during a battery change.
Finding the OBD2 Port Location on a 2015 WRX
The 2015 Wrx Obd2 Port Location is typically situated under the driver’s side dashboard. Look for it in the area above the pedals and below the steering column. It’s usually easily accessible and not hidden behind panels, though you might need to crouch down to see it clearly.
Alt text: The typical OBD2 port location under the dashboard on the driver’s side of a vehicle, similar to where it would be found in a 2015 Subaru WRX.
While the image is a general representation, the location is consistent for most vehicles and accurately reflects where you’ll find it in your 2015 WRX. It’s a 16-pin connector, trapezoidal in shape.
Using the OBD2 Port to Preserve Memory: Proceed with Caution
While using the OBD2 port is a common technique, it’s crucial to proceed with caution:
- Use a Memory Saver Device: The safest approach is to use a dedicated memory saver device. These devices are designed to provide a stable 12V power supply through the OBD2 port and often include fuse protection.
- 7.5 Amp Fuse Limitation: As the original article mentions, the circuit is often protected by a 7.5 Amp fuse. Do not exceed this current draw.
- Ensure All Accessories are OFF: Before disconnecting the battery and connecting your power source, make absolutely sure that all accessories in your 2015 WRX are turned off. This includes headlights, interior lights, radio, and climate control. Even opening a door can activate interior lights and potentially blow the fuse if the current draw exceeds 7.5 Amps.
- Step-by-Step Process (General Guidance – Consult your WRX Service Manual):
- Turn off the ignition and all accessories.
- Locate the OBD2 port on your 2015 WRX.
- Connect your memory saver device to the OBD2 port.
- Verify the memory saver is providing power before disconnecting the car battery.
- Disconnect the negative battery terminal first, then the positive.
- Replace the battery.
- Reconnect the positive battery terminal first, then the negative.
- Disconnect the memory saver device.
- Start your 2015 WRX and check if your settings have been preserved.
Potential Issues and Important Considerations
- Blown Fuse: If you accidentally draw too much current (e.g., by opening a door and turning on interior lights), you can blow the 7.5 Amp fuse protecting the OBD2 port circuit. This will interrupt the power supply and defeat the purpose of using the memory saver. If this happens, you’ll need to replace the fuse (refer to your owner’s manual for fuse box location and fuse type).
- Incorrect Polarity: Connecting the power source with reversed polarity can damage your car’s electrical system. Always double-check polarity and use a device with proper protection.
- Not a Solution for All Issues: Maintaining power through the OBD2 port prevents memory loss during battery changes. It is not related to check engine lights (CELs) or other diagnostic issues. A blown fuse in this circuit will not cause a CEL, but it can prevent a code reader from working if it relies on the car’s power.
Conclusion
Knowing the 2015 WRX OBD2 port location and how to use it for memory preservation can save you time and frustration during battery changes. However, always exercise caution, use proper equipment like a memory saver device, and ensure all accessories are off to avoid blowing fuses or causing electrical issues. If you are uncomfortable with this procedure, it’s always best to consult a qualified mechanic for battery replacement and memory preservation services on your 2015 Subaru WRX.
