P280F
Reductant Pump Control Circuit - OpenP280F is a generic OBD-II powertrain diagnostic trouble code: Reductant Pump Control Circuit - Open. It is logged by the engine control unit when the powertrain monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.
What P280F means
P280F is stored when the ECM detects an open circuit in the control circuit for the reductant supply or high-pressure pump. The module commands the pump via a driver output and monitors the return signal or current sense to confirm the pump has responded. When no load is detected on the circuit — indicating a broken wire, failed connector, or failed pump motor winding — P280F is set and reductant delivery is suspended.
Open-circuit faults on the pump control line most commonly arise from corrosion at the pump harness connector, which is located near the reductant tank in the vehicle undercarriage and exposed to road debris and moisture. Wiring that runs along the undercarriage is also susceptible to chafing, rodent damage, and physical abrasion. Less frequently, the pump motor winding itself fails open due to thermal stress or manufacturing defect.
With the pump unable to operate, no reductant is delivered to the SCR catalyst regardless of DEF fluid level or quality. The vehicle will emit elevated NOx and, depending on OEM calibration, may enter a progressive derate strategy. The fault must be corrected to restore SCR system function and regulatory compliance.
Common causes
Most-frequently reported root causes when P280F is logged.
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1
Open (broken) wire in the pump control or power supply harness.
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2
Corroded or disconnected pump harness connector causing an open circuit.
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3
Failed pump motor winding open-circuited due to thermal damage or wear.
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4
Blown fuse in the pump supply circuit removing power from the motor.
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5
Damaged wiring from road debris, chafing, or rodent activity.
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6
Failed ECM pump driver circuit providing no output to the pump.
Symptoms drivers notice
How to diagnose P280F
A typical diagnostic flow when this code is present.
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1
Record all DTCs and freeze-frame data before any repairs.
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2
Inspect the reductant pump harness connector at the pump end for corrosion, pulled-out terminals, or physical damage.
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3
Check the pump supply fuse in the fuse box and replace if blown; investigate the cause before simply re-fusing.
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4
With the pump connector unplugged, measure continuity of the control and power supply wires back to the ECM using a wiring diagram.
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5
Measure pump motor resistance at the pump terminals; an open reading (infinite resistance) confirms a failed motor winding.
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6
Inspect the full harness run from the ECM to the pump for chafing, crushing, or visible breaks, especially at undercarriage routing clips.
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7
If wiring, connector, and fuse all check out, test the ECM driver output per OEM procedure and replace the pump assembly or ECM as guided by results.
Vehicles where we've handled P280F
Platforms in our catalogue with confirmed P280F coverage.
Related powertrain codes
Frequently asked questions
Can I bypass the pump to get the vehicle moving?
Bypassing the pump removes SCR functionality entirely and would cause the vehicle to emit illegal NOx levels. It is not recommended and may itself trigger additional faults or derates.
Why would the pump motor fail open?
Thermal cycling, extended operation with low or contaminated DEF, and manufacturing variability can all cause the motor winding insulation to fail, breaking the electrical path and creating an open circuit.
Is P280F the same as the pump being seized?
Not necessarily. An open circuit may mean the motor is electrically disconnected but mechanically intact. A seized pump would typically set an overcurrent or feedback fault rather than an open-circuit code.
Will clearing the code re-enable the pump?
Clearing the code resets the fault flag but does not repair the underlying open circuit. The pump will remain inoperative until the electrical fault is physically corrected.
Disabling P280F in software
RaceTune can permanently disable P280F — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.
ECUs with a P280F disable in our catalogue
Confirmed coverage from our recipe database — we support many more families. Upload your file and our identifier will match it automatically.
- Bosch EDC17C50 verified 1 software version
- Bosch EDC17C56 verified 1 software version
- Bosch MD1CP002 verified 1 software version
- Bosch MD1CS001 verified 1 software version
Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.
Got P280F in your scan?
Upload your ECU file — we'll identify the exact software version and confirm whether a disable is available for your car.
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