Powertrain, generic (extended)

P2370 Fuel Volume Regulator B Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

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.

Likely causes

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

Symptoms

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

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–2,500
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

fuel volume regulator bhigh pressure fuel pumpfuel volume regulator wiring

Related codes

P2371P2372P2373P0001P0087P0088

References: newtonnet.co.uk, fordservicecontent.com, en.wikipedia.org, gsi.ext.gm.com.