What could cause my tach and speedometer needle to suddenly not work then p0335 comes up

Hi, this is Bo, an auto expert on RepairPal's Car Genius team! If your tachometer and speedometer are acting up and you're seeing a P0335 code, it points directly to the crankshaft position sensor. This sensor plays a critical role in engine timing, and if it's failing or has a poor connection, it can cause your gauges to stop working and trigger the check engine light. It might not immediately cause rough running, but it's a sign things could go south quickly if left unresolved. Since you’ve been dealing with this for a few months, double-check the wiring and connections to the crankshaft position sensor—look for any loose connections, frayed wires, or corrosion. If all looks good, it might be time to replace the sensor itself. This should help restore your gauges and keep that engine light off for good! If you need any further advice or if you'd like any help finding a trusted RepairPal shop in your area, please feel free to call us at 877-913-1554!