P220B
Reductant Pump PerformanceP220B is a generic OBD-II powertrain diagnostic trouble code: Reductant Pump Performance. 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 P220B means
P220B is stored when the SCR control module determines that the reductant pump is not performing within the expected parameters during operation. Unlike circuit high or low codes, P220B is a functional or rationality fault, meaning the wiring and electrical connections may appear intact but the pump is not delivering the expected flow or pressure response under commanded conditions.
This code is typically detected by cross-referencing the commanded pump duty cycle or speed against the resulting reductant pressure buildup. If the pressure response does not match the commanded output within calibrated tolerances, the module concludes that the pump has degraded mechanically or is suffering from a partial electrical fault that the circuit-level diagnostics did not catch.
Common causes include a worn or partially seized pump motor, a partially blocked inlet screen or filter, air ingestion from a low DEF level, and internal pump check valve leakage allowing pressure bleed-back. Diagnosis requires a scan tool capable of reading pump command versus pressure response live data to confirm whether the fault is mechanical or partially electrical in nature.
Common causes
Most-frequently reported root causes when P220B is logged.
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1
Worn or partially seized reductant pump motor reducing output flow.
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2
Partially clogged reductant inlet filter or screen restricting pump suction.
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3
Low DEF level causing the pump to ingest air and cavitate.
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4
Leaking internal pump check valve allowing pressure bleed-back between cycles.
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5
Degraded pump motor brushes or commutator reducing effective output.
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6
Partially blocked dosing injector creating back-pressure that masks pump underperformance.
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7
Intermittent supply voltage drop to the pump causing reduced motor speed.
Symptoms drivers notice
How to diagnose P220B
A typical diagnostic flow when this code is present.
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1
Retrieve all DTCs and freeze-frame data; note any accompanying pressure or NOx efficiency codes.
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2
Verify the DEF tank level is adequate and the fluid is not frozen or contaminated.
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3
Inspect and clean or replace the reductant inlet filter or strainer.
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4
With a scan tool, command the pump to run and observe live pressure buildup rate against the commanded duty cycle.
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5
Measure supply voltage at the pump connector during operation to rule out voltage drop.
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6
If pressure buildup is sluggish despite correct voltage and clean filter, the pump motor is likely mechanically degraded.
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7
Replace the reductant pump assembly and perform a system prime and verification cycle.
Vehicles where we've handled P220B
Platforms in our catalogue with confirmed P220B coverage.
Related powertrain codes
Frequently asked questions
How is P220B different from P208C (pressure too low)?
P208C is a threshold fault triggered when pressure falls below a fixed minimum. P220B is a performance or rationality fault triggered when pump response does not match what is commanded, even if the actual pressure has not yet crossed the P208C threshold.
Can a dirty DEF filter alone cause P220B?
Yes. A partially blocked inlet filter creates suction restriction that reduces pump output, which the module can detect as a performance fault before pressure drops enough to set P208C.
Will P220B resolve itself if I top off the DEF tank?
If low DEF causing cavitation was the only cause, refilling and priming the system may allow the code to clear. However, if the pump is mechanically worn, refilling will not resolve the fault.
Does P220B require pump replacement in all cases?
Not always. Cleaning the inlet filter, refilling DEF, and verifying wiring may resolve the fault. Pump replacement is appropriate only after eliminating these simpler causes.
Disabling P220B in software
RaceTune can permanently disable P220B — 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 P220B 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 EDC17CP57 verified 2 software versions
- Bosch EDC17C66 verified 1 software version
- Bosch EDC17C74 verified 1 software version
- Bosch EDC17CP44 verified 1 software version
- Bosch MD1CP004 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.
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