P2C35
Turbocharger/Supercharger Intake Air Flow Control Position Sensor/Switch Circuit LowP2C35 is a generic OBD-II powertrain diagnostic trouble code: Turbocharger/Supercharger Intake Air Flow Control Position Sensor/Switch 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.
What P2C35 means
P2C35 is stored when the ECM measures a voltage below the expected minimum on the intake air flow control position sensor signal circuit. A low signal voltage typically results from a short to ground on the sensor signal wire, a loss of sensor supply voltage, or a failed sensor whose output has collapsed to ground potential.
The position sensor provides closed-loop feedback for the intake air flow control actuator. When the signal is abnormally low, the ECM cannot determine true valve position and defaults to an open-loop strategy. Depending on the system, the actuator may park in a fixed default position or the ECM may continue commanding based on estimated position, leading to suboptimal combustion control.
Because the signal circuit shares the 5-volt reference supply path with other sensors in many ECM designs, a short to ground on this circuit could also affect adjacent sensors sharing the same reference. Confirming that companion sensor codes are not present helps scope the fault. Signal circuit shorts to ground are usually located by disconnecting sensors one at a time and watching for the reference voltage to recover.
Common causes
Most-frequently reported root causes when P2C35 is logged.
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1
Short to ground on the position sensor signal wire.
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2
Loss of 5-volt reference supply to the sensor, causing the signal to collapse low.
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3
Failed sensor element with its output shorted internally to ground.
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4
Damaged connector with a terminal shorted to the connector shell or chassis.
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5
Wiring insulation failure due to heat or mechanical chafe near the sensor.
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6
Shared reference voltage supply short affecting multiple sensors simultaneously.
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7
ECM internal reference supply fault pulling the sensor excitation low.
Symptoms drivers notice
How to diagnose P2C35
A typical diagnostic flow when this code is present.
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1
Read all stored codes; identify whether multiple sensor codes with low voltage suggest a shared reference fault.
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2
Inspect the sensor connector and wiring harness for shorts to ground.
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3
Measure the 5-volt reference voltage at the sensor connector; absence of reference confirms a supply fault.
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4
With the sensor unplugged, check if the reference voltage recovers at the ECM connector, isolating the fault to the sensor itself.
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5
Measure the signal wire resistance to chassis ground with the circuit unplugged to confirm or rule out a harness short.
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6
If reference voltage and harness are good, replace the position sensor or actuator assembly.
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7
Clear codes, verify signal voltage operates within range across the actuator travel, and road test.
Vehicles where we've handled P2C35
Platforms in our catalogue with confirmed P2C35 coverage.
Related powertrain codes
- P2C20 — Turbocharger/Supercharger Boost Control A Circuit Open
- P2C21 — Turbocharger/Supercharger Boost Control A Circuit Low
- P2C22 — Reductant Pump Performance
- P2C2B — Turbocharger/Supercharger Boost Control B Circuit Open
- P2C2C — Turbocharger/Supercharger Boost Control B Circuit Low
- P2C30 — Reductant Tank Level Sensor Circuit - High
Frequently asked questions
How do I tell if the 5-volt reference is the problem rather than the sensor?
Unplug the sensor and measure voltage on the reference wire at the connector. If 5 volts returns after unplugging, the sensor is pulling the reference low internally. If it remains low, the fault is in the harness or ECM.
Can a low position sensor signal affect boost pressure?
Indirectly. If the ECM cannot confirm valve position, it may alter boost management strategy. However, P2C35 directly refers to the position sensor circuit, not the boost pressure circuit.
Is P2C35 more common in cold or hot conditions?
Both. Cold ambient temperatures can cause connector seal compression failures, while heat can soften insulation leading to shorts. Intermittent faults that appear under heat often point to wiring close to hot engine components.
Do I need a scan tool with bidirectional control to diagnose P2C35?
A basic scan tool that can read live data is sufficient to monitor the sensor voltage. Bidirectional control helps confirm actuator response but is not mandatory for diagnosing the sensor circuit.
Disabling P2C35 in software
RaceTune can permanently disable P2C35 — 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 P2C35 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.
Got P2C35 in your scan?
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