Tell me your and engine type (Gas vs. Diesel). Share if you see three bars or a standard engine light .
Mention any made to the battery or transmission.
: Inspect the electrical connectors on the transmission actuator for corrosion or loose pins. Re-teaching or "learning" the transmission via a STAR diagnostic tool often resolves software-based blockages. 2. EVAP System Failure If the car is a gasoline model where the code is literal: smart p2403.40h
: On many Smart diesel or older gasoline models, users report this code alongside transmission "limp mode," where the car may show three horizontal bars on the dash and refuse to shift. Common Symptoms
: The car gets stuck in gear or refuses to engage a gear. Tell me your and engine type (Gas vs
: A faulty leak detection pump or a break in the wiring to the sensor.
🛠️ : Because generic scanners often misread this code as an emissions issue on vehicles that may not even have that specific EVAP setup (like diesel Smarts), a professional diagnosis is vital. 1. Transmission Actuator Issues Mention any made to the battery or transmission
: Frayed wires near the gearbox or a failing Ground (GND) connection .