Damaged, chafed or broken wiring between the control unit and the fuel volume regulator solenoid; Corroded, loose or pushed-out pins in the solenoid connector or control unit connector; Open circuit inside the fuel volume regulator solenoid winding; Blown fuse or faulty relay in the supply feed, where fitted; Fault in the fuel pump assembly that houses the regulator; Internal driver fault in the engine control unit.

P00CB

Fuel Volume Regulator Solenoid Supply Voltage Control Circuit/Open.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
0: AreaFuel and air metering, auxiliary emission controls
CB: FaultThe specific fault in that area

What it means

P00CB means the engine control unit has found an open circuit in the supply voltage control side of the fuel volume regulator solenoid. This solenoid, often called the inlet metering valve, usually sits on the fuel pump and controls how much fuel goes to the high pressure side. The control unit sets the code when the commanded supply voltage or current does not match what it measures, which points to a break in the circuit. Exact circuit layout varies by engine and model.

Symptoms

Engine warning light on
Reduced power or limp mode
Hard starting or long cranking
Engine stalling or cutting out
Rough running or hesitation under load
Fuel rail pressure fault codes stored alongside

Possible causes

Damaged, chafed or broken wiring between the control unit and the fuel volume regulator solenoidlikely
Corroded, loose or pushed-out pins in the solenoid connector or control unit connectorlikely
Open circuit inside the fuel volume regulator solenoid windinglikely
Blown fuse or faulty relay in the supply feed, where fittedpossible
Fault in the fuel pump assembly that houses the regulatorpossible
Internal driver fault in the engine control unitrare

How to diagnose

Read all stored codes and freeze frame data, noting engine speed, load and rail pressure when the fault set, and check for related fuel pressure codes.
Check the service information for this engine to find the solenoid supply circuit, fuse and relay layout.
Visually inspect the wiring and connector at the solenoid for damage, heat, fuel contamination, corrosion and bent or loose pins.
Check the relevant fuse and relay, and confirm the supply voltage is present at the solenoid connector with the ignition on.
With the connector unplugged, measure the solenoid winding resistance and compare it with the manufacturer specification.
Test the wiring for continuity from the solenoid connector to the control unit, and check for shorts to earth or to supply.
Wiggle the harness while monitoring live data to find intermittent breaks.
Only after the wiring and solenoid check out, consider the pump assembly or control unit, and follow the manufacturer's procedure.

How to fix

Repair or replace damaged wiring, using proper soldered and sealed joints rather than twisting or taping wires.
Clean or replace corroded connectors and correct any loose terminals.
Replace the fuel volume regulator solenoid if its winding is open or out of specification, following the model procedure.
Replace a blown fuse or faulty relay once the cause of the failure has been found.
Replace the fuel pump assembly if the regulator is not serviced separately and is faulty.
Clear the code after repair and road test to confirm it does not return.

Can I keep driving?

Medium severity

The car may run in limp mode or stall unexpectedly, so avoid long journeys and book a repair soon. If it cuts out, loses power or struggles to start, stop driving until it is fixed.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.