Code U0603 indicates that the engine control module (PCM) has lost communication with the fuel pressure sensor. This means the PCM is not receiving the required data signal to monitor and regulate fuel rail pressure.
Internal electronic failure of the sensor prevents it from sending data to the PCM.
Chafed, broken, or shorted wires between the sensor and the PCM interrupt the communication signal.
Moisture or debris in the sensor connector leads to poor electrical contact or signal degradation.
A blown fuse or faulty ground circuit prevents the sensor from receiving the voltage necessary to operate.
A failure in the PCM's processing circuit for the fuel pressure input, though this is rare.
No. U0603 is rarely caused by a failed PCM. It is far more common for the issue to be a failed sensor, damaged wiring, or a poor connection.
The vehicle may be drivable, but it will likely operate in a default fuel pressure mode, leading to poor performance and potentially damaging other components over time.
Yes, if the communication loss is caused by corrosion or debris creating high resistance at the pins, cleaning with electrical contact cleaner may resolve the issue.