P2370: Fuel Volume Regulator B Control Circuit Open
An open circuit is detected on the control line for the second fuel volume regulator (B) used on twin high-pressure-pump diesel systems. Without this regulator the high-pressure pump cannot meter fuel for its assigned cylinder bank, leading to rail-pressure faults and limp-home behaviour.
What P2370 means
P2370 is a generic OBD-II powertrain code in the fuel & air group. In plain English: the computer found an electrical fault in that circuit: an open, short or bad connection, or a failed component.
- Check engine light
- Usually on
- Emissions-related
- Yes — can fail inspection
- Limp mode possible
- Not typical
- Drive cycle to clear
- Not required
Get it fixed
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Common causes
- 01Open in harness or connector to regulator BMost likely
- 02Regulator solenoid winding openPossible
- 03Pin pushed back out of connector bodyLess likely
Can I drive with P2370?
Usually yes, for a short time.
The car will often drive normally, but get it diagnosed soon. Left alone it can raise fuel use and emissions and will fail an OBD inspection. If you notice rough running, warning lights flashing, overheating or a burning smell, stop driving.
Why we rate it moderate
- Turns on the check engine light
- Emissions-related: will usually fail an OBD inspection
Severity is our rule-based rating from the code’s flags in OBDex and the system it affects, not an inspection of your car. If the check engine light is flashing, or you notice overheating, low oil pressure, or brake or steering problems, stop driving and get help.
How to diagnose P2370
- 1
Confirm the code and save freeze-frame data
Read the codes with an OBD-II scan tool and note every code, not just P2370. Save the freeze-frame data (speed, load, temperature when the fault set) before clearing anything; it tells you when the fault happens.
- 2
Fix other faults first
If other codes are stored, start with power-supply, sensor-circuit and communication codes. They can cause this code as a side effect.
- 3
Test the circuit
Inspect the wiring and connector at the fuel volume regulator b and high pressure pump b for damage, corrosion or chafing. With a multimeter, check supply voltage, ground and signal against the specifications in the service manual for your vehicle.
- 4
Test the likely causes in order
Start with the most likely cause and work down: Open in harness or connector to regulator B; regulator solenoid winding open; pin pushed back out of connector body. Test before replacing parts.
- 5
Check for recalls and service bulletins
Look up recalls for your exact vehicle with its VIN, and ask a dealer about technical service bulletins (TSBs). Manufacturers sometimes issue software updates or extended warranties for known faults.
- 6
Clear the code and verify the repair
After the repair, clear the code and drive the car under the conditions in the freeze-frame data to confirm it does not return.
P2370 repair cost estimate
Estimate, not a quote. Labor times are typical ranges for this code from OBDex, and $125/hr is an assumed rate. Shop rates and labor times vary by vehicle and region. Diagnosis time may be billed separately.
- DIY difficulty
- Moderate
- Good DIY job?
- Usually a shop job
Needs a scan tool and some experience with testing.
Parts and systems involved
- Fuel volume regulator B
- High pressure pump B
- Fuel rail
P2370 FAQ
What does P2370 mean?
P2370 means “Fuel Volume Regulator B Control Circuit Open”. An open circuit is detected on the control line for the second fuel volume regulator (B) used on twin high-pressure-pump diesel systems. Without this regulator the high-pressure pump cannot meter fuel for its assigned cylinder bank, leading to rail-pressure faults and limp-home behaviour.
Is P2370 serious? Can I keep driving?
We rate P2370 as moderate severity. Usually yes, for a short time. The car will often drive normally, but get it diagnosed soon. Left alone it can raise fuel use and emissions and will fail an OBD inspection. If you notice rough running, warning lights flashing, overheating or a burning smell, stop driving.
What causes P2370?
The most common causes, from most to least likely: Open in harness or connector to regulator B; Regulator solenoid winding open; Pin pushed back out of connector body. Test before replacing parts, because several causes can set the same code.
How much does it cost to fix P2370?
Typical labor is about $125–$375 at an assumed $125/hour shop rate, plus parts. That is an estimate, not a quote: labor times and rates vary by vehicle and region, and diagnosis may be billed separately.
Can I fix P2370 myself?
DIY difficulty is moderate. Most owners leave this to a shop because it needs involved testing or specialist tools. Always confirm the cause before buying parts.
Will P2370 clear itself?
If the fault was intermittent, the warning may go off once the computer stops seeing it, but the code stays in memory. Fix the cause; clearing the code alone doesn’t repair anything.