P0252: Injection Pump Fuel Metering Control A Range/Performance
The P0252 code indicates that the Engine Control Module (ECM) has detected a range or performance problem in the fuel metering control circuit 'A' of the injection pump. This circuit typically involves the cam, rotor, or injector position sensors within the pump. The ECM monitors the fuel quantity actuator or timing device and compares actual fuel delivery to commanded delivery. A discrepancy beyond expected limits triggers this code, often due to mechanical wear, electrical faults, or fuel contamination.
01. Most Common Causes
- Faulty injection pump fuel metering actuator
- Worn or damaged cam/rotor inside injection pump
- Electrical issues: open/short in wiring or connectors to fuel metering control
- Contaminated fuel causing internal pump damage
- Failed ECM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine hard to start or no start
- Loss of power and poor acceleration
- Rough idle or engine misfire
- Excessive smoke from exhaust (black or white)
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and freeze frame data to confirm P0252.
Step 2: Visually inspect wiring and connectors at injection pump for damage, corrosion, or loose connections.
Step 3: Test fuel pressure and quality; check for water or debris in fuel.
Step 4: Use a scan tool to command fuel metering actuator and observe actual vs. desired values.
Step 5: Perform injection pump mechanical tests (e.g., timing, internal wear) per manufacturer service manual.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
No, driving with P0252 can cause poor performance, stalling, or no start. Continued driving may damage the injection pump or engine.
How much does it cost to fix?▼
Repair costs range from $200 to $800 depending on the cause. Simple wiring fixes are cheaper; injection pump replacement can be $500-$1500 including labor.