The P0815 code in your 2023 Mercedes-Benz AMG C43 indicates a malfunction in the upshift switch circuit. This typically refers to the paddle shifter or manual mode upshift control that allows drivers to manually select higher gears.
Understanding the Upshift Switch
The AMG C43 features steering wheel-mounted paddle shifters for manual gear selection in Sport and Sport+ modes. The upshift paddle sends a signal to the TCM requesting a higher gear. P0815 indicates this circuit has a problem.
Common Causes of P0815
- Faulty upshift paddle switch
- Wiring damage in steering column
- Clock spring (contact ring) failure
- TCM input circuit malfunction
- Corroded connector
- Software/communication error
Symptoms of Upshift Switch Failure
- Upshift paddle not responding
- Delayed upshift command
- Check engine light on
- Sport mode affected
- Manual shift mode limited
- Downshift paddle may still work
AMG Performance Considerations
The C43 AMG's driving experience relies heavily on manual gear selection capability. P0815 affects the driver's ability to optimize shift points for performance driving.