P0237
Turbocharger/Supercharger Boost Sensor "A" Circuit Low
The boost pressure A signal voltage is below the lower diagnostic threshold — open circuit, short to ground, or sensor element failure.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
Common causes
Ordered by how often each turns out to be the cause.
- Sensor circuit shorted to ground or openCommon
- Boost pressure sensor failedPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Boost Pressure Sensor
- Boost Sensor Wiring
P0237 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.