What Does P0259 Mean?
The ECM has detected that the injection pump fuel metering control 'B' signal or output is below the expected minimum threshold. This means the secondary fuel metering solenoid is not achieving the minimum commanded fuel delivery rate, resulting in insufficient fuel being metered by the injection pump. The engine may run lean, lack power, or stall under load.
Common Causes
35%
Open circuit in the fuel metering solenoid B wiring or connector causing low or no current flow
25%
High resistance in the fuel metering solenoid B coil due to internal degradation
20%
ECM driver circuit providing insufficient voltage or current to the metering solenoid
20%
Poor ground connection for the injection pump metering circuit
Diagnostic Steps
1
Step 1: Measure voltage at the fuel metering solenoid B connector with the engine running — verify battery voltage is present on the supply wire when the ECM commands the solenoid on.
2
Step 2: Check solenoid resistance with a DVOM — compare to manufacturer specification. Higher than spec resistance indicates a failing coil causing low current flow.
3
Step 3: Perform a voltage drop test on the ground circuit from the solenoid connector to the ECM ground pin — should be less than 0.3V. Check all engine grounds for corrosion.
4
Step 4: Backprobe the ECM connector and verify the driver output signal matches the commanded duty cycle — use an oscilloscope to verify proper signal amplitude and waveform.
5
Step 5: If all wiring tests pass but the code persists, swap the metering solenoid with a known-good unit and retest to confirm solenoid failure vs ECM issue.
Estimated Repair Cost
$150 - $1,200
Parts + labor, varies by vehicle and location
The ECM has detected that the injection pump fuel metering control 'B' signal or output is below the expected minimum threshold. This means the secondary fuel metering solenoid is not achieving the minimum commanded fuel delivery rate, resulting in insufficient fuel being metered by the injection pu...
The most common cause of P0259 (Injection Pump Fuel Metering Control "B" Low (Cam/Rotor/Injector)) is: Open circuit in the fuel metering solenoid B wiring or connector causing low or no current flow
Typical repair costs for P0259 range from $150 to $1,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may experience significant power loss and potential stalling under load. Drivable at reduced speeds but repair should be prioritized to avoid being stranded.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0259 to identify the root cause.
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Quick Info
Category
Powertrain
System
Diesel Fuel Injection System
Difficulty
Type
Generic (SAE)
Recommended Tools
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