What it means
Injection Pump Fuel Metering Control A Range/Performance (Cam/Rotor/Injector): the signal is implausible or outside the valid range. This affects fueling of the associated cylinders.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
Injection-pump fuel metering control A regulates fuel delivery, while its feedback lets the control module judge whether the metering response is plausible. P0252 sets when control A's response is outside the expected range or does not match the commanded operation. That can cause incorrect fueling and reduced power.
Common causes
Most likely first.
- Actuator drifted
- Sensor element aged beyond calibration window
- Sensor mounting loose - signal damping
Symptoms
- Check-engine light on
- Hard starting or no start
- Rough running
- Reduced engine power
How to diagnose it
- Record freeze-frame data and compare commanded with reported control A position or metering data to identify when the mismatch occurs.
- Inspect control A's connector, wiring, and mounting for looseness, corrosion, damage, or vibration that could disturb its signal.
- Check the fuel supply for restriction, air ingress, or contamination that may make metering response appear out of range.
- Use scan-tool data to observe whether control A responds smoothly as the command changes, if the vehicle exposes that data.
- Test the actuator, feedback signal, and circuit against the manufacturer's specification before deciding whether calibration or pump repair is needed.
Common fixes
- Secure a loose control A connector or mounting point and repair damaged wiring.
- Correct a fuel-supply restriction or air leak that affects metering response.
- Replace a control A actuator or sensor that fails the manufacturer's tests.
- Repair or calibrate the injection pump only when testing confirms it is outside specification.
Can I keep driving?
Avoid heavy loads and long trips if starting is difficult, the engine runs roughly, or power is reduced; the fault can progress to stalling or a no-start condition. Arrange diagnosis soon, especially if drivability is worsening.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.