P006C

MAP - Turbocharger/Supercharger Inlet Pressure Correlation

P006C is a generic OBD-II powertrain diagnostic trouble code: MAP - Turbocharger/Supercharger Inlet Pressure Correlation. It is logged by the engine control unit when the turbo/boost monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.

Code
P006C
Group
Powertrain
System
Turbo/Boost
Severity
Warning (MIL on, possible limp mode)
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What P006C means

Code P006C is set when the Powertrain Control Module (PCM) detects a persistent mismatch between the signal from the Manifold Absolute Pressure (MAP) sensor and the signal from the turbocharger or supercharger inlet pressure sensor. On forced-induction engines, the inlet pressure sensor is typically located upstream of the compressor wheel or supercharger inlet to measure the pressure of air entering the boosting device, while the MAP sensor measures the resulting pressurised air in the intake manifold downstream of the compressor. Both readings must be physically consistent — the inlet pressure before the compressor must always be lower than the boosted manifold pressure during normal operation. The PCM compares these two signals continuously; if they deviate beyond a calibrated tolerance for a set period, P006C is stored and the Malfunction Indicator Lamp illuminates. Typical triggers include a failed inlet pressure sensor, an air intake restriction that reduces pre-compressor pressure below expected levels, a boost leak between the compressor outlet and the intake manifold that causes manifold pressure to drop relative to what the PCM expects, or wiring faults distorting one of the sensor signals. Because incorrect pressure data directly affects boost target calculations, fuel trim, and turbocharger vane or wastegate control, this fault can substantially degrade driveability and engine efficiency.

Common causes

Most-frequently reported root causes when P006C is logged.

  • 1
    Defective turbocharger or supercharger inlet pressure sensor with drifted or fixed output
  • 2
    Faulty MAP sensor producing an inaccurate post-compressor pressure reading
  • 3
    Boost leak between the compressor outlet and intake manifold (intercooler hoses, clamps, or charge pipe cracks) reducing measured manifold pressure
  • 4
    Restricted air intake or severely clogged air filter reducing pre-compressor pressure below expected levels
  • 5
    Open, shorted, or corroded wiring and connector terminals in either sensor circuit
  • 6
    Insufficient engine vacuum caused by an intake manifold gasket leak or cracked vacuum hose
  • 7
    PCM calibration or software error misinterpreting sensor correlation thresholds

Symptoms drivers notice

Malfunction Indicator Lamp (check engine light) illuminated
Reduced engine power, especially noticeable during acceleration or under heavy load
Delayed throttle response or turbo lag greater than normal
Hesitation or stumble during acceleration caused by incorrect boost management
Decreased fuel economy as the PCM cannot optimise fuelling without accurate pressure data
Audible hissing or suction noise from the intake area indicating a boost or vacuum leak

How to diagnose P006C

A typical diagnostic flow when this code is present.

  1. 1
    Connect an OBD-II scanner, retrieve all stored codes and freeze frame data; note engine speed and load at fault set, and check for companion turbocharger or intake codes
  2. 2
    Inspect the air intake path from the air filter housing to the turbocharger inlet for blockages, collapsed ducting, or loose clamps; also check all intercooler hoses and charge pipes for cracks or disconnected clamps
  3. 3
    Check the air filter condition and replace if heavily contaminated, as restriction before the compressor directly affects the inlet pressure reading
  4. 4
    With the engine running, use scanner live data to compare the turbocharger inlet pressure sensor and MAP sensor readings simultaneously; identify which sensor value is inconsistent with expected operating pressure
  5. 5
    Perform a boost leak test by pressurising the intake system (engine off) to the manufacturer-specified pressure and listening or using soapy water to locate leaks in intercooler hoses, pipe joints, or the throttle body
  6. 6
    Test 5 V reference supply, signal voltage, and ground continuity at both sensor connectors with a digital multimeter; verify sensor output tracks correctly when vacuum or pressure is applied via a hand pump
  7. 7
    Clear stored codes, conduct a test drive under boost conditions, and confirm whether P006C resets; if it does, proceed to PCM-level pin testing per the OEM wiring diagram

Related powertrain codes

Frequently asked questions

Can a boost leak trigger P006C even if no physical intake damage is visible?

Yes. Small cracks in silicone intercooler hoses or slightly loose hose clamps may not be obvious visually but can release enough pressure under boost to cause a measurable discrepancy between inlet and manifold pressure. A dedicated boost leak test with the intake pressurised is the most reliable way to find these leaks.

Does P006C only affect turbocharged vehicles?

Yes. The turbocharger or supercharger inlet pressure sensor is specific to forced-induction engines. Naturally aspirated vehicles do not have this sensor and will not generate P006C.

Will the engine enter limp mode with P006C?

It depends on the manufacturer and the severity of the pressure discrepancy. Many PCMs will limit boost pressure or restrict engine torque as a protective measure when they cannot trust the inlet pressure data, which manifests as reduced power. Full limp mode limiting vehicle speed is possible if the PCM judges the discrepancy severe enough.

How is P006C different from a standard boost pressure code like P0234 or P0299?

P0234 (overboost) and P0299 (underboost) are set when the measured boost level falls outside acceptable limits. P006C is a correlation code — it means the inlet pressure sensor and the MAP sensor are giving readings that do not agree with each other, regardless of whether either individual value is outside absolute limits. A sensor that has drifted but still reads within range can cause P006C without triggering a dedicated overboost or underboost code.

Disabling P006C in software

RaceTune can permanently disable P006C — 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.

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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