P2C67

Reductant Level Sensor Circuit Low

P2C67 is a generic OBD-II powertrain diagnostic trouble code: Reductant Level Sensor Circuit Low. 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.

Code
P2C67
Group
Powertrain
System
Powertrain
Severity
Warning (MIL on)
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What P2C67 means

P2C67 is stored when the ECM or SCR control module detects that the voltage signal from the diesel exhaust fluid (DEF/AdBlue) level sensor circuit is below the calibrated minimum threshold. The reductant level sensor monitors the quantity of DEF in the tank, which is critical for SCR system operation and for alerting the driver to low fluid conditions before a derate condition is triggered.

A low circuit signal prevents the system from accurately reporting DEF level. The module may display an incorrect level reading, disable level-based warnings, or in some calibrations trigger a precautionary derate. Regulatory requirements in many markets mandate that persistent reductant system faults result in torque reduction if not addressed within a set number of engine starts.

The fault is commonly caused by a short to ground on the signal wire, a damaged or waterlogged sensor, or a broken connection at the DEF tank sender unit. Inspect the DEF tank wiring harness, which is often exposed to road contamination and mechanical damage.

Common causes

Most-frequently reported root causes when P2C67 is logged.

  • 1
    Short to ground on the reductant level sensor signal wire.
  • 2
    Failed level sensor with output below minimum voltage.
  • 3
    Corroded or damaged connector at the DEF tank sender.
  • 4
    Open 5V reference or sensor supply circuit.
  • 5
    Water or DEF fluid ingress into the sensor or connector.
  • 6
    Damaged harness routed near the vehicle undercarriage.
  • 7
    Faulty SCR control module input channel.

Symptoms drivers notice

MIL or SCR warning lamp illuminated.
Inaccurate or missing DEF level reading on the instrument cluster.
Possible premature DEF low warning even with a full tank.
Risk of progressive torque derate if fault persists across multiple start cycles.
SCR system may enter degraded operation mode.

How to diagnose P2C67

A typical diagnostic flow when this code is present.

  1. 1
    Connect scan tool and read all active, pending, and stored DTCs in the SCR or aftertreatment module.
  2. 2
    Check live DEF level sensor voltage; confirm reading below minimum threshold.
  3. 3
    Inspect DEF tank sender connector and wiring for corrosion, moisture, or damage.
  4. 4
    Measure 5V reference supply at the sensor connector with ignition on.
  5. 5
    Check signal wire for short to ground with sensor disconnected.
  6. 6
    Test sensor resistance or voltage output off-vehicle if accessible.
  7. 7
    Replace sender unit if wiring and supply are verified satisfactory.

Vehicles where we've handled P2C67

Platforms in our catalogue with confirmed P2C67 coverage.

BMW 320D
2016

Related powertrain codes

Frequently asked questions

Can a nearly empty DEF tank cause P2C67?

No. A genuinely low DEF level triggers a separate low-level warning code. P2C67 is an electrical circuit fault independent of actual fluid quantity.

Will P2C67 cause a torque derate immediately?

Not immediately in most systems; regulatory logic typically allows a grace period of engine starts before enforcing derate, but the fault should be repaired promptly.

Is the DEF level sensor integrated with the DEF pump?

On many vehicles the level sensor, temperature sensor, and quality sensor are combined in one sender module inside the DEF tank; a single unit replacement may address all related faults.

Can freezing DEF damage the sensor?

DEF freezes at approximately -11 degrees Celsius; repeated freeze-thaw cycles can stress sensor connections and seals, making this a potential cause in cold climates.

Disabling P2C67 in software

RaceTune can permanently disable P2C67 — 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.

Permanent
The monitor is disabled in the ECU itself — not just cleared. It cannot return.
Tailored to your file
Each patch is matched to your specific software version — never a one-size-fits-all file.
Reversible
The original file is always preserved. Reflash the stock to return the ECU to factory state.

ECUs with a P2C67 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

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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