What Does P0001 Mean?
P0001 indicates an open circuit in the fuel volume regulator (FVR) control circuit. The fuel volume regulator, typically found on diesel common rail and gasoline direct injection (GDI) systems, controls fuel pressure by metering the amount of fuel entering the high-pressure pump. When this circuit is open, the ECM cannot control fuel rail pressure properly. The driver may experience hard starting, reduced power, rough idle, or engine stalling.
Safety Warning
Driving is not recommended. Without fuel pressure regulation, the engine may stall unexpectedly, especially under load or at highway speeds. The high-pressure fuel system may also default to maximum pressure, risking damage to injectors and fuel rails. Have this repaired before driving.
Common Causes
35%
Broken or corroded wiring in the fuel volume regulator control circuit between the ECM and the FVR solenoid
30%
Failed fuel volume regulator solenoid with an open internal coil winding
15%
Poor ground connection for the FVR circuit causing the ECM to interpret the circuit as open
10%
ECM driver circuit failure preventing the module from commanding the FVR solenoid
10%
Connector pin backed out or improperly seated at the FVR solenoid or ECM, creating an intermittent open
Diagnostic Steps
1
Locate the fuel volume regulator on the high-pressure fuel pump and disconnect its electrical connector — inspect for corrosion, bent pins, or moisture intrusion.
2
Measure the FVR solenoid coil resistance with a multimeter — typical spec is 1-6 ohms depending on manufacturer. An infinite (OL) reading confirms an open coil.
3
Perform a continuity test on each wire from the FVR solenoid connector back to the ECM connector to verify no open circuits exist in the harness.
4
With the ignition on and engine off, backprobe the ECM connector and verify the ECM is providing a command voltage (typically 12V pulsed) to the FVR circuit.
5
Check the engine ground straps for looseness or corrosion, particularly those from the engine block to the chassis and from the engine block to the negative battery terminal.
Estimated Repair Cost
$150 - $800
Parts + labor, varies by vehicle and location
P0001 indicates an open circuit in the fuel volume regulator (FVR) control circuit. The fuel volume regulator, typically found on diesel common rail and gasoline direct injection (GDI) systems, controls fuel pressure by metering the amount of fuel entering the high-pressure pump. When this circuit i...
The most common cause of P0001 (Fuel Volume Regulator Control Circuit / Open) is: Broken or corroded wiring in the fuel volume regulator control circuit between the ECM and the FVR solenoid
Typical repair costs for P0001 range from $150 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Driving is not recommended. Without fuel pressure regulation, the engine may stall unexpectedly, especially under load or at highway speeds. The high-pressure fuel system may also default to maximum pressure, risking damage to injectors and fuel rails. Have this repaired before driving.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0001 to identify the root cause.
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Quick Info
Category
Powertrain
System
Fuel System
Difficulty
Type
Generic (SAE)
Recommended Tools
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