P2370: Fuel Volume Regulator B Control Circuit/Open

A fuel volume regulator is the solenoid valve at the high-pressure pump that decides how much of the pump's stroke reaches the rail. Regulator B only exists where a second valve or second pump is fitted – the 5.2 litre V10 of Audi and Lamborghini, for instance, has two cam-driven high-pressure pumps for its two rails. No manufacturer documents P2370 publicly; GM's 2025 diesel table handles a second metering valve under P233A–P233C instead. The A counterparts show the logic: Ford wires its gasoline FVR with both high and low side to the PCM and monitors it continuously, and Ford's 2023 diesel sees an open valve as 2.8–4.8 V at the driver while the valve is off. Without current, delivery from pump B depends on the valve's resting state.

Medium severity. Can I keep driving?Avoid long trips and hard acceleration. If you smell fuel or the car stalls, do not continue.

Symptoms

Check engine light on
Rail pressure deviation and possible reduced power
Hard starting

Most likely causes

Connector at regulator B loose or corroded
Regulator coil burnt open
Broken high-side or low-side wire

What to check, in order

Start with the simplest. You can tick off each step.

Check the pump's fuse, relay, and connector
Check the continuity of the wire between the component and the control module.
Replace the filter if it is due for maintenance
Compare commanded and actual pressure in live data
Measure the pressure with a suitable gauge
Check the sensor and regulator before replacing the pump

Good to know

Repair difficulty: medium
It can trigger limp mode.
It affects emissions.

What each character of P2370 means

P: Powertrain: engine and transmission
2: Generic code: same on every make
3: Ignition and misfires
70: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2370?

Avoid long trips and hard acceleration. If you smell fuel or the car stalls, do not continue.

What causes code P2370?

The most common causes are: connector at regulator B loose or corroded; regulator coil burnt open; broken high-side or low-side wire.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.