The OBDII (On-Board Diagnostics II) port on a 2017 Subaru Crosstrek is crucial for diagnostics and maintenance. This port allows mechanics and car owners to access the vehicle’s computer system and retrieve diagnostic trouble codes (DTCs), monitor performance data, and even program certain modules. Understanding its location and function can be helpful for troubleshooting issues and ensuring your Crosstrek runs smoothly.
Locating the OBDII port is usually straightforward. In most vehicles, including the 2017 Subaru Crosstrek, it’s found under the driver’s side dashboard, often near the steering column or the fuse box. It’s a standardized 16-pin trapezoidal connector.
While the OBDII port primarily serves diagnostic purposes, it also plays a role in maintaining power to certain vehicle systems when the main battery is disconnected. Disconnecting the battery can result in the loss of learned data in various control modules, affecting the car’s optimized performance. Radio presets and the clock are also affected by battery disconnection.
Unlike some vehicles where the accessory power outlet remains constantly powered, allowing for a 12V supply to maintain system memory, Subarus do not have this feature. This means alternative methods are necessary to prevent data loss during battery disconnection.
One method involves using the OBDII port’s pin 16, which has a constant power supply. A specialized adapter can connect a 12V source, such as a portable battery, to this pin via the OBDII port, often utilizing a 7.5 Amp fuse for protection.
However, this method requires caution. While sufficient for maintaining minimal power to modules, exceeding the 7.5 Amp limit can blow the fuse. This can occur if any significant electrical load is activated, like interior lights when a door is opened. A blown fuse results in the same data loss as a complete battery disconnect.
Symptoms of a blown OBDII power supply fuse include a reset clock and radio, and potentially rough idling until the engine control module (ECM) relearns its operational parameters. If a battery replacement results in these symptoms, a blown fuse in the OBDII power supply circuit is a possible cause. Importantly, a blown fuse in this circuit doesn’t trigger a Check Engine Light (CEL), but it can prevent code readers from functioning if they rely on the car’s power. Knowing how to access and utilize the OBDII port correctly is vital for both troubleshooting and maintaining your 2017 Subaru Crosstrek.
