The P0873 code in your 2023 Subaru Legacy indicates the torque converter clutch slip speed sensor circuit is providing higher readings than expected. This affects the CVT's ability to monitor TCC operation accurately.
Legacy CVT and TCC
The Subaru Legacy uses a Lineartronic CVT with a torque converter for smooth launches. High slip speed readings may indicate sensor circuit issues or actual excessive slip that needs attention.
Common Causes of P0873
- Open circuit in sensor ground
- Short to battery voltage
- Sensor internal failure
- Actual excessive TCC slip
- CVT fluid contamination
- Torque converter wear
Symptoms of High Sensor Input
- TCC monitoring issues
- Check engine light on
- CVT may limit TCC lockup
- Fuel economy reduction
- Possible CVT protection modes
- Inaccurate diagnostic data
Subaru CVT Maintenance
The Legacy's CVT requires specific Subaru CVT fluid and regular maintenance. Fluid condition directly affects TCC and overall CVT operation.