Smart P2403.40h -

If your Smart is throwing the P2403.40h code, you might notice:

: This is a sub-code used by Mercedes-Benz/Smart internal systems (like STAR/Xentry). It often denotes a functional failure or a "signal defect". smart p2403.40h

Tell me your and engine type (Gas vs. Diesel). Share if you see three bars or a standard engine light . If your Smart is throwing the P2403

: The car gets stuck in gear or refuses to engage a gear. Diesel)

: Clean ground points and check the wiring harness for "chafing" common in Smart 450/451 engine bays. Summary Table Likely Issue Typical Action Transmission Actuator Physical blockage or signal loss Clean connectors; run adaptation EVAP Pump Circuit open or pump failure Replace pump; check vacuum lines Wiring Harness Chafed or corroded wires Repair wiring; check ground points ECU/PCM Software glitch Clear codes and re-scan with STAR If you'd like to troubleshoot this further: