Injection Pump Fuel Metering Control B Low (Cam/Rotor/Injector)
P0258 indicates the fuel injection pump's metering control circuit is detecting a low voltage or signal condition. This code typically appears in diesel engines where the fuel metering control system fails to maintain proper pressure regulation, affecting fuel delivery precision and engine performance.
What You Might Notice
- Check Engine Light illumination
- Decreased fuel economy
- Rough idle or unstable engine operation
- Reduced engine power or acceleration
- Difficulty starting the engine
Most Common Causes
- 1
Fuel Rail Pressure Sensor electrical fault
A short to ground or open circuit in the FRP sensor signal or power circuit prevents proper voltage communication to the PCM. This is the most common cause on diesel engines.
- 2
Fuel injection pump control circuit wiring damage
Corroded, loose, or damaged wiring harness connections between the pump metering control solenoid and the PCM disrupt signal transmission.
- 3
Failed fuel metering control solenoid
The solenoid that regulates fuel flow through the injection pump may be stuck, failed electrically, or mechanically stuck in the low-flow position.
- 4
PCM programming issue or module failure
In rare cases, outdated PCM software or a failed powertrain control module may cause false low signal readings despite sensor functionality.
How to Diagnose It
- 1
Check Fuel Rail Pressure Sensor electrical fault — A short to ground or open circuit in the FRP sensor signal or power circuit prevents proper voltage communication to the PCM. This is the most common cause on diesel engines.
- 2
Check Fuel injection pump control circuit wiring damage — Corroded, loose, or damaged wiring harness connections between the pump metering control solenoid and the PCM disrupt signal transmission.
- 3
Check Failed fuel metering control solenoid — The solenoid that regulates fuel flow through the injection pump may be stuck, failed electrically, or mechanically stuck in the low-flow position.
- 4
Check PCM programming issue or module failure — In rare cases, outdated PCM software or a failed powertrain control module may cause false low signal readings despite sensor functionality.
How to Fix It
- 1
Inspect and test fuel rail pressure sensor
Use a multimeter to check the FRP sensor voltage output and wiring continuity. Replace the sensor if voltage readings are out of specification or circuits show open/short conditions.
- 2
Repair fuel metering control circuit wiring
Inspect the harness from the injection pump to the PCM for corrosion, damage, or loose connectors. Clean contacts thoroughly and repair or replace damaged wire segments.
- 3
Replace fuel metering control solenoid
If electrical tests pass but the code persists, the solenoid controlling fuel metering in the pump is likely stuck or failed. Remove and replace with a new unit.
- 4
Check for technical service bulletins and reprogram PCM
Consult manufacturer TSBs for your specific vehicle model, as this code may be a known issue with a software update. Update or reprogram the PCM if applicable.
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