P0003 indicates that the powertrain control module (PCM) has detected a low voltage condition in the fuel volume regulator control circuit. This circuit controls the solenoid that regulates fuel pressure in the fuel rail, typically on direct-injection engines. A low voltage reading suggests a short to ground, open circuit, or a faulty regulator solenoid.
The solenoid inside the fuel pressure regulator can fail internally, causing a low resistance or short to ground that pulls the control circuit voltage down.
A chafed, pinched, or melted wire in the regulator control circuit can create a direct path to ground, lowering the circuit voltage.
A broken wire, corroded terminal, or unseated connector can interrupt the circuit, causing the PCM to see a low or no voltage condition.
Although rare, a failed driver transistor or internal short within the PCM can cause a low voltage reading. This should only be considered after all wiring and the solenoid have been verified.
It is not recommended. A low voltage condition in the fuel volume regulator circuit can cause incorrect fuel pressure, leading to poor engine performance, stalling, or potential damage to the fuel system. Have the issue diagnosed and repaired promptly.
No. The PCM is rarely the root cause. Most often the problem is a faulty fuel volume regulator solenoid, a wiring short, or a connector issue. Replacing the PCM without first checking the solenoid and wiring is a common and costly mistake.
It means the PCM is detecting a voltage on the control circuit that is below the expected threshold (typically near battery voltage when the circuit is off, or a specific pulse-width-modulated signal when active). This usually indicates a short to ground or an open circuit.
It is possible but unlikely. Extremely low system voltage (below 9V) can cause the PCM to misinterpret circuit voltages. However, a properly charged battery and functioning alternator should not trigger this code. If the battery is very weak, address that first and then recheck for the code.