What it means
The engine control module detects an intermittent fault in the injection pump fuel metering control "B" circuit or signal. It sets the code when the monitored control behaves erratically or drops out under the conditions specified by the vehicle calibration.
How it works
The injection pump fuel metering control B circuit governs metering by the pump's actuator, with the exact arrangement depending on the engine. The engine control module monitors the B circuit or signal and sets P0260 when its operation intermittently behaves erratically or drops out.
Common causes
Most likely first.
- Intermittent wiring or connector fault
- Failing fuel metering control actuator
- Poor electrical connection or corrosion
- Faulty injection pump
- Engine control module fault
Symptoms
- Hard starting
- Rough running or hesitation
- Reduced engine power
- Check engine light
How to diagnose it
- Save freeze-frame data and review fuel metering command and feedback data to see when the intermittent B-circuit fault occurred.
- Inspect the injection pump control B connector and harness for loose or corroded terminals, damaged insulation, or movement-related contact loss.
- Monitor the B-circuit signal while gently moving the harness to locate an intermittent connection.
- Test the B-circuit wiring and connector continuity, supply, and ground using the manufacturer's diagram and specifications.
- If the circuit checks out, test the fuel metering actuator and injection pump, then consider the engine control module only after other causes are ruled out.
Common fixes
- Reseat the fuel metering control B connector and secure loose wiring.
- Repair damaged or corroded circuit connections.
- Replace the fuel metering control actuator if its intermittent failure is confirmed.
- Repair or replace the injection pump if testing confirms an internal fault.
Can I keep driving?
Hard starting, hesitation, or reduced power may become worse or lead to stalling. Avoid demanding acceleration and do not continue driving if the engine stalls or power becomes unpredictable.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.