P0237 on the 6.7L Power Stroke is a turbocharger boost sensor A circuit low input fault. The 6.7L uses a boost, or manifold absolute pressure, sensor to report intake pressure to the PCM, which uses it to control fueling, boost from the variable geometry turbo, and smoke management. P0237 sets when the PCM reads a boost sensor voltage too low, indicating a short to ground, an open, or a failed sensor.
The boost signal is important to how the 6.7L manages power and emissions, so a low reading can lead to reduced power or a derate. P0237 is an electrical circuit code, which points first at the sensor wiring, the connector, and the sensor itself rather than at the turbo. Confirming the circuit before touching the turbocharger keeps you from chasing an expensive part when the fix is a wire or a sensor.
What P0237 means
The boost sensor outputs a voltage that rises with intake pressure. P0237 sets when that voltage stays at the low end of the scale, indicating a signal wire shorted to ground, a lost reference, an open circuit, or a sensor that has failed low. The PCM cannot trust the boost reading and may limit power in response.
Common causes
- Signal wire shorted to ground
- Lost 5-volt reference to the sensor
- Open in the signal or reference circuit
- Corroded or loose boost sensor connector
- Failed boost sensor
Symptoms
- Reduced power or limp mode
- Check engine light with P0237 stored
- Poor throttle response and sluggish acceleration
- Boost gauge reading that does not match performance
- Companion boost or turbo codes
How to diagnose it
With a scan tool, view the boost sensor value key on, engine off; it should read close to barometric pressure. A value pinned low at rest confirms the fault. Inspect the sensor connector for corrosion, water, and a secure fit. Back-probe the connector and confirm the 5-volt reference and ground. Check the signal wire for a short to ground and confirm continuity back to the PCM. If the reference and ground are good but the signal stays low, the sensor is the likely fault.
How to fix it
Repair a signal wire shorted to ground, restore a lost reference, and clean or replace a corroded connector first. If the reference and ground reach the sensor but the signal stays low, replace the boost sensor. After the repair, clear the code, confirm the sensor reads barometric pressure at key on and boost builds correctly under load, and road test. For the correct boost sensor or connector for your 6.7L Power Stroke, contact sales@coredieselparts.com.
Frequently asked questions
Is P0237 a turbo problem?
Usually not. It is a boost sensor circuit code, so check the sensor wiring, connector, and reference before suspecting the turbo. The sensor or its wiring is the common cause.
What is the difference between P0237 and P0238?
P0237 is the boost sensor circuit reading too low and P0238 is the same circuit reading too high. Both point at the boost sensor and its wiring, from opposite electrical directions.
Will P0237 cause a derate?
It can. Without a trustworthy boost signal the PCM may limit power to protect the engine until the circuit is repaired.
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