The fuel volume regulator (also called metering unit or suction control valve) is a solenoid valve on the inlet side of the high-pressure pump, used mainly on common-rail diesel engines. The engine control module pulses it to set how much fuel the pump draws in and delivers to the rail, and in this way controls rail pressure. With P0002 the circuit is electrically intact, but command and effect do not match: the measured current does not fit the duty cycle, or rail pressure does not follow the regulator position plausibly. The cause is often mechanical, for example a sticking valve, rather than the wiring.
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
- Loss of power or limp mode
- Jerking or unstable idle
- Hard starting or stalling
Most likely causes
- Regulator sticking or worn due to dirt, debris or water in the fuel
- High resistance at connector or wiring causing wrong current
- Low-pressure supply problem: clogged filter or air in the fuel
- Rail pressure sensor reading wrong values
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: hard
- It can trigger limp mode.
- It affects emissions.
What each character of P0002 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 0: Subsystem depends on the code range
- 02: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0002?
Avoid long trips and hard acceleration. If you smell fuel or the car stalls, do not continue.
What causes code P0002?
The most common causes are: regulator sticking or worn due to dirt, debris or water in the fuel; high resistance at connector or wiring causing wrong current; low-pressure supply problem: clogged filter or air in the fuel.
Related codes
- P0001Fuel Volume Regulator A Control Circuit/Open
- P0003Fuel Volume Regulator A Control Circuit Low
- P0004Fuel Volume Regulator A Control Circuit High
- P000EFuel Volume Regulator Control Exceeded Learning Limit
- P0087Fuel Rail/System Pressure - Too Low
- P0088Fuel Rail/System Pressure - Too High
- P0089Fuel Pressure Regulator A Performance
- P0191Fuel Rail Pressure Sensor A Circuit Range/Performance
Sources
- law.cornell.edu: 13 CCR 1968.2
- bosch-mobility.com: high pressure pump cp4
- denso-am.eu: common rail suction control valve scv
- de.wikipedia.org: Common Rail Einspritzung
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.