P0251: Injection Pump Fuel Metering Control Malfunction
The P0251 code indicates a malfunction in the fuel metering control system of the injection pump, specifically related to the cam, rotor, or injector. This system regulates the amount of fuel delivered to the engine. When the Powertrain Control Module (PCM) detects an issue with the fuel metering control circuit or component, it sets this code. Common causes include a faulty fuel metering solenoid, wiring issues, or internal pump failure. This can lead to poor engine performance, hard starting, and reduced fuel efficiency.
01. Most Common Causes
- Faulty fuel metering solenoid
- Wiring or connector issues in the fuel metering control circuit
- Internal injection pump failure (cam, rotor, or injector)
- Contaminated fuel causing pump damage
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine hard to start or no start
- Reduced engine power and poor acceleration
- Rough idle or engine misfire
- Decreased fuel economy
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and freeze frame data to identify related issues.
Step 2: Visually inspect the injection pump wiring and connectors for damage, corrosion, or loose connections.
Step 3: Test the fuel metering solenoid resistance and voltage supply using a multimeter; compare to manufacturer specifications.
Step 4: Check fuel pressure and quality; contaminated fuel may require system cleaning.
Step 5: If all else is normal, suspect internal pump failure and consider replacement or professional rebuild.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with P0251 as it can cause poor engine performance, stalling, or no start. Continued driving may damage the injection pump or other components.
How much does it cost to fix?▼
Diagnosis typically costs $50-$150. Repair costs vary: a fuel metering solenoid replacement may be $200-$400, while a full injection pump replacement can range from $1,000 to $2,500 or more.