Injection Pump Fuel Metering Control B High
The P0259 code indicates that the Engine Control Module (ECM) has detected a high voltage signal from the fuel metering control circuit B of the injection pump. This circuit controls the amount of fuel delivered to the injectors based on engine demand. A high voltage reading suggests a short to power, faulty actuator, or internal pump failure, leading to potential over-fueling or erratic engine performance.
01. Most Common Causes
- Faulty fuel metering control actuator
- Short to power in the control circuit wiring
- Internal injection pump failure
- Corroded or damaged connector at the injection pump
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine running rough or misfiring
- Excessive black smoke from exhaust
- Poor fuel economy and reduced power
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and record freeze frame data.
Step 2: Visually inspect the injection pump wiring and connector for damage, corrosion, or loose pins.
Step 3: Use a multimeter to check the voltage at the fuel metering control actuator connector; compare to manufacturer specifications.
Step 4: Perform a resistance test on the actuator solenoid; replace if out of range.
Step 5: If wiring and actuator are okay, suspect internal pump failure and consult a specialist.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Driving with P0259 can cause poor engine performance, increased emissions, and potential damage to the injection pump or engine.
How much does it cost to fix?▼
Repair costs vary from $200 to $800 depending on the cause. Wiring repairs are cheaper, while injection pump replacement can be expensive.