P2C36

Turbocharger/Supercharger Intake Air Flow Control Position Sensor/Switch Circuit High

P2C36 is a generic OBD-II powertrain diagnostic trouble code: Turbocharger/Supercharger Intake Air Flow Control Position Sensor/Switch Circuit High. 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
P2C36
Group
Powertrain
System
Powertrain
Severity
Warning (MIL on)
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What P2C36 means

P2C36 is set when the ECM detects a voltage above the expected maximum on the intake air flow control position sensor signal circuit. A high signal voltage condition typically results from a short to the reference supply voltage or to battery voltage on the sensor signal wire, causing the ECM to read an implausibly high position value.

With the signal voltage pinned high, the ECM interprets the valve as being at maximum travel continuously, regardless of its actual position. Closed-loop control is compromised, and the ECM may default to open-loop operation. In practice, the physical valve position is unaffected by the sensor fault, but the ECM cannot verify or correct it, reducing system efficiency and potentially increasing emissions.

A short to the 5-volt reference on the signal circuit is the most common cause, often resulting from a pinched harness where the signal and reference wires run adjacent. Measuring voltage on the signal wire with the sensor connector unplugged quickly distinguishes a harness short from an internally failed sensor. An internally failed sensor will show no parasitic voltage on the harness when disconnected.

Common causes

Most-frequently reported root causes when P2C36 is logged.

  • 1
    Short between the sensor signal wire and the 5-volt reference wire in the harness.
  • 2
    Short to battery or switched ignition voltage on the sensor signal wire.
  • 3
    Internally failed position sensor with the output shorted to the reference supply.
  • 4
    Pinched wiring harness causing adjacent wires to contact each other.
  • 5
    Wiring repair that inadvertently connected the signal wire to a higher voltage source.
  • 6
    Damaged connector with a terminal bridged to the reference terminal.
  • 7
    ECM internal fault causing the signal input to read high regardless of sensor condition.

Symptoms drivers notice

MIL illuminated.
Intake air flow position sensor reads maximum value on scan tool regardless of actual valve position.
Intake actuator control reverts to open-loop or default mode.
Subtle changes in low-load or idle combustion quality.
No actuator response during scan tool activation because feedback is always saturated.

How to diagnose P2C36

A typical diagnostic flow when this code is present.

  1. 1
    Read all codes and freeze-frame data; check for companion codes on adjacent sensor circuits.
  2. 2
    Inspect the position sensor harness for pinching or contact between signal and reference wires.
  3. 3
    Unplug the sensor and measure voltage on the signal wire at the harness connector; voltage present confirms a short to voltage in the harness.
  4. 4
    Trace the harness back toward the ECM, separating wire groupings to locate the point of contact.
  5. 5
    If no harness voltage is found with the sensor disconnected, replace the sensor or actuator assembly.
  6. 6
    After repair, verify that the signal voltage tracks smoothly across the actuator travel range.
  7. 7
    Clear codes and perform a road test to confirm no return.

Vehicles where we've handled P2C36

Platforms in our catalogue with confirmed P2C36 coverage.

BMW 320D
2016

Related powertrain codes

Frequently asked questions

Is a signal-to-reference short always a harness fault?

Usually yes, but an internally shorted sensor can also cause the same symptom. Unplugging the sensor and checking whether voltage disappears from the signal wire distinguishes these two scenarios.

Can P2C36 cause the actuator to move to an extreme position?

The sensor circuit fault does not directly command the actuator; it only prevents the ECM from reading its position. The actuator position is determined by the ECM command signal, not the feedback signal.

Would a scan tool reset fix P2C36?

Clearing codes removes the stored fault, but P2C36 will return on the next drive cycle if the underlying short or sensor fault remains unresolved.

Is P2C36 emissions-relevant?

Yes. Because the MIL is illuminated, the vehicle will fail an OBD-based emissions check. Additionally, imprecise intake air flow control can increase particulate or NOx emissions in real-world driving.

Disabling P2C36 in software

RaceTune can permanently disable P2C36 — 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 P2C36 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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