What does code 25 mean on a 2000 Nissan Frontier?

Code 25 on a 2000 Nissan Frontier typically indicates an issue with the vehicle's engine coolant temperature sensor. This code suggests that the sensor may be malfunctioning, which can affect engine performance and fuel efficiency. It’s important to diagnose the problem accurately, as it could also point to wiring issues or a faulty engine control unit (ECU). Addressing this code usually involves inspecting or replacing the coolant temperature sensor and checking related wiring.