P2374: Turbocharger/Supercharger Inlet Pressure Sensor B Circuit
What to do
Not urgent — boost management gets cautious while the reading is missing. Wiring and connector first; and since this sensor exists partly to watch the air filter, a filter overdue for service is worth ruling out while anyone is in there.
What this code means
The sensor measuring pressure before the second turbocharger's compressor has failed its circuit checks — a sensor most people do not know exists, watching the one part of the intake everyone forgets.
Before the compressor, the intake runs below atmospheric pressure, because the turbo is sucking through the air filter and ducting. That depression is a measurement with two jobs: it is how the module monitors filter restriction honestly (a clogging filter deepens the depression at any given flow — a service reminder computed from physics rather than mileage), and it protects the compressor itself, whose safe operating range depends on inlet conditions. The B designator places this on twin-turbo installations — one sensor per turbo's inlet on engines where each bank breathes separately.
Losing the sensor costs monitoring rather than drive: expect conservative boost and a lit lamp rather than drama. The wiring lives in the intake tract's vibration and heat; it leads the suspects as ever.
Likely causes
Start here
- Open circuit in sensor wiring · moderate
- Corroded or loose connector · easy
Less common
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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