P0237 means Turbocharger/Supercharger Boost Sensor A Circuit Low. The boost sensor signal voltage is lower than possible, usually an open circuit or a short to ground. It is a generic OBD-II code, so the definition is the same on any make, but the most likely cause varies by engine; confirm with a scan tool and the service information for your vehicle before buying parts.
What P0237 means
Modern engines measure boost and fuel rail pressure and compare them with a desired value calculated from engine speed, load and throttle. When actual pressure falls short of desired for long enough, the computer sets a code and often reduces power to protect the engine. Watching desired and actual values side by side on a scan tool shows whether the shortfall is constant or only appears under load.
P0237 symptoms
- Reduced-power mode
- Loss of boost
Common causes of P0237
- Open in the reference or signal wire
- Shorted signal to ground
- Failed sensor
How to diagnose P0237
- Check the connector and wiring
- Check the 5-volt reference and ground
- Replace the sensor if wiring tests good
Can you drive with P0237?
Gently; power is usually limited.
P0237 tips
If several sensor codes set at the same time, a shorted sensor may be pulling down a shared 5-volt reference; see P0641. Boost sensors on diesels sit in a dirty, oily environment, so check the connector for oil and corrosion and the harness for chafing against brackets or hot pipes. With the engine off, a healthy sensor reads close to barometric pressure, which gives a quick sanity check before replacing it.
Will P0237 clear itself?
If the fault stops, the computer turns off the check engine light by itself after several drive cycles without seeing it again, and the code stays in memory as history for a while. Clearing P0237 with a scan tool after a repair is fine, but if the cause is still there the code returns, sometimes within one drive. Disconnecting the battery also clears codes on most vehicles, but it erases learned fuel trims and idle settings as well.
Related codes
| Code | Meaning |
|---|---|
| P0236 | Turbocharger/Supercharger Boost Sensor A Circuit Range/Performance |
| P0238 | Turbocharger/Supercharger Boost Sensor A Circuit High |
| P0641 | Sensor Reference Voltage A Circuit/Open |
Guides that help
When it is more than a sensor
Our superchargers page lists supercharger kits, and diesel owners can read the 6.7 Cummins turbo guide. If a failed turbo or fuel pump has damaged the engine, compare engines by code on our engines page.
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