The P0253 code on your 2020 Subaru Crosstrek indicates an injection pump fuel metering control circuit low input condition. Since this code relates to diesel injection systems and the Crosstrek uses gasoline Boxer engines, understanding why it appeared is the first diagnostic step.
Crosstrek Engine Configuration
The 2020 Crosstrek is powered by Subaru's 2.0L or 2.5L horizontally-opposed (Boxer) gasoline engines. Subaru offers diesel engines in some international markets, but not in North America. The fuel injection system is direct injection (on 2.5L) or port injection, neither of which uses the type of injection pump that P0253 monitors.
Code Appearance Analysis
P0253 appearing on your Crosstrek suggests a diagnostic system anomaly. Possible causes include: aftermarket diagnostic tool misreading Subaru-specific protocols, ECM software corruption, electromagnetic interference affecting ECM signal processing, or wiring issues creating phantom signals. Some aftermarket performance tuners can also cause unusual code storage.
Recommended Diagnostics
Read codes using Subaru Select Monitor (SSM) for accurate interpretation. Check for pending or history codes that might indicate actual issues. If using an aftermarket tuner, verify it's compatible with your ECM version. Inspect the engine wiring harness, particularly around the fuel system, for damage.
Resolution
Clear the code and drive normally to see if it returns. If SSM doesn't show the code, consider the original reading inaccurate. For persistent unexplained codes, Subaru dealer diagnostics can verify ECM integrity and check for software updates that might address erroneous code storage.