P2C37

Turbocharger/Supercharger Boost Control A Position Sensor Circuit Low

P2C37 is a generic OBD-II powertrain diagnostic trouble code: Turbocharger/Supercharger Boost Control A Position 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
P2C37
Group
Powertrain
System
Powertrain
Severity
Warning (MIL on, possible limp mode)
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What P2C37 means

P2C37 is stored when the ECM detects a voltage reading from the boost pressure or vane position sensor circuit A that is below the expected minimum threshold. The sensor is used to monitor the position of variable geometry turbocharger (VGT) vanes or a boost actuator, allowing closed-loop boost control.

When the signal falls below the calibrated low limit, the ECM cannot accurately determine boost actuator position. This prevents proper boost regulation and may cause the engine to enter a reduced-power or limp mode to protect the turbocharger and emission systems from damage.

The fault is typically triggered by a short to ground in the sensor signal wire, a failed sensor with an internal short, a damaged connector with moisture ingress, or loss of sensor supply voltage. Inspect wiring and connectors at the turbocharger actuator before condemning the sensor itself.

Common causes

Most-frequently reported root causes when P2C37 is logged.

  • 1
    Sensor signal wire shorted to ground.
  • 2
    Failed boost position sensor with internal short circuit.
  • 3
    Corroded or damaged connector at the turbocharger actuator.
  • 4
    Open or high-resistance in the sensor 5V reference supply wire.
  • 5
    ECM 5V reference circuit fault affecting multiple sensors.
  • 6
    Turbocharger actuator mechanically seized causing sensor over-travel.
  • 7
    Water or oil ingress into the sensor or connector.

Symptoms drivers notice

MIL illuminated.
Reduced engine power or limp mode active.
Noticeable lack of turbo boost under acceleration.
Possible excessive smoke from exhaust due to fueling without boost feedback.
Engine may feel sluggish at all throttle positions.

How to diagnose P2C37

A typical diagnostic flow when this code is present.

  1. 1
    Connect a scan tool and record all stored DTCs and freeze frame data.
  2. 2
    Check live sensor voltage for the boost position sensor; low circuit expects above minimum threshold (typically above 0.2V).
  3. 3
    Inspect the wiring harness and connector at the turbocharger actuator for chafing, corrosion, or moisture.
  4. 4
    Measure the 5V reference voltage at the sensor connector with ignition on.
  5. 5
    Perform a continuity check of the signal wire between sensor and ECM for a short to ground.
  6. 6
    Substitute a known-good sensor or use a breakout box to verify ECM pin voltage.
  7. 7
    Replace sensor if wiring and supply voltage are confirmed good and fault persists.

Vehicles where we've handled P2C37

Platforms in our catalogue with confirmed P2C37 coverage.

BMW 320D
2016

Related powertrain codes

Frequently asked questions

Can I drive with P2C37 active?

Short distances may be possible if the vehicle is not in full limp mode, but continued driving risks turbocharger damage and should be avoided until repaired.

Will clearing the code fix it?

No. The code will return on the next drive cycle unless the underlying wiring or sensor fault is corrected.

Could a dirty sensor cause this code?

Contamination alone rarely causes a low circuit code; a short to ground or loss of supply voltage is the more likely cause.

Is P2C37 the same as P0234?

No. P0234 is an overboost condition, while P2C37 is specifically a low-voltage electrical fault in the boost control position sensor circuit A.

Disabling P2C37 in software

RaceTune can permanently disable P2C37 — 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 P2C37 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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