Powertrain, generic · Fuel and air metering, auxiliary emission controls

P0002 Fuel Volume Regulator A Control Circuit Range/Performance

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modePossible

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.

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

Symptoms

Check engine light on
Loss of power or limp mode
Jerking or unstable idle
Hard starting or stalling

Repair estimate

DifficultyHardWorkshop job

Parts and labour€100–3,000

Time1–4 h

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

Parts involved

fuel volume regulatorhigh pressure fuel pumpfuel volume regulator wiring

References: law.cornell.edu, bosch-mobility.com, denso-am.eu, de.wikipedia.org.