HomeTrouble CodesP2370

P2370 — Fuel Volume Regulator B Control Circuitopen

Manufacturer-specificPowertrain (engine & transmission)

P2370 means the engine control module has detected an open electrical circuit in the control path for the 'B' fuel volume regulator, also called a fuel metering or inlet metering valve on many common-rail fuel systems. An open circuit prevents the module from commanding the regulator, so fuel delivery and rail pressure cannot be properly controlled. This typically turns on the malfunction indicator lamp and may force the engine into a reduced-power or no-start condition.

Symptoms

What causes it — most likely first

1. Faulty fuel volume regulator / metering valve solenoid

The regulator coil can open internally, so the PCM sees infinite resistance on the control circuit and sets the code.

2. Open, chafed, or broken wiring in the regulator control circuit

A break anywhere between the PCM driver and the regulator solenoid creates the open-circuit condition the code reports.

3. Corroded, loose, or damaged electrical connector / pins

Poor contact at the regulator or harness connector adds resistance or creates a complete open, causing the same circuit fault.

4. Blown fuse or faulty relay protecting the regulator circuit

If the regulator's power supply is fused or relay-controlled, loss of power to the solenoid can be reported as a control-circuit open.

5. PCM / ECM driver failure

A failed output driver inside the control module is possible but uncommon; it should only be considered after the regulator, wiring, and power/ground are proven good.

How it's diagnosed

  1. Visually inspect the regulator connector and harness for damage, corrosion, pin push-out, or chafing
  2. Check any fuses and relays that feed the fuel volume regulator circuit
  3. Measure the regulator solenoid resistance and compare with the manufacturer's specification
  4. Test supply voltage, ground, and the PCM control signal at the regulator connector with the key on/engine running as appropriate
  5. Perform a continuity and short-to-ground test on the wiring between the regulator connector and the PCM
  6. Evaluate the PCM only if the regulator, power, ground, and all wiring are confirmed to be within specification

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationManufacturer-specific (P1/B1/C1/U1)

Frequently asked

Is it safe to keep driving with P2370?

No. The engine may stall, fail to restart, or enter limp mode, so the vehicle should be diagnosed and repaired before regular driving resumes.

Should I replace the PCM for P2370?

Usually no. PCM failure is one of the least likely causes of this code. Most cases are caused by a failed fuel volume regulator, wiring damage, or a connector problem.

What does 'Fuel Volume Regulator B' actually do?

It is a solenoid-controlled valve, often an inlet metering valve on a common-rail high-pressure fuel pump, that regulates how much fuel enters the pump to control rail pressure. The 'B' identifier refers to a second or secondary regulator on the vehicle.

Can a blown fuse cause this code?

Yes, if the regulator circuit is fused. A missing power supply can be interpreted as an open control circuit, so fuses should be checked before replacing any components.