Turbo/Supercharger Boost Sensor B Circuit Low
The P0237 code means the vehicle's onboard diagnostic system has detected: Turbo/Supercharger Boost Sensor B Circuit Low. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- moderate
- Estimated cost
- $80 - $350 (parts and labor)
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Common Symptoms
- Check Engine Light illuminated
- Engine in limp mode with no boost
- Significant loss of power
- Boost gauge shows zero or minimal boost
Probable Causes (Ranked by Likelihood)
- Short to ground in boost sensor B signal wire Very High
- Failed boost pressure sensor B (shorted) High
- Corroded connector at sensor Moderate
- PCM input shorted Low
Step-by-Step Diagnostic Procedure
-
Read boost sensor B voltage. Below 0.3V at key-on engine-off confirms low circuit.
-
Disconnect sensor and check signal wire for short to ground.
-
Inspect connector for corrosion or moisture ingress.
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With sensor disconnected, verify PCM provides reference voltage (typically 5V) on the supply wire.
Frequently Asked Questions
What does circuit low mean for the boost sensor?
The PCM receives a voltage below the normal range from boost sensor B, typically from a short to ground in the wiring or a failed sensor.
Will the turbo still work with P0237?
The PCM will likely disable or limit turbo boost as a safety measure, resulting in a significant power loss.
Can water cause P0237?
Yes, water intrusion into the sensor connector from road spray or engine washing can short the signal wire to ground.
Sources
This page is built from documented references. Verify against your own service info before repair work.
P0237 on Diesel, EV & Equipment
The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:
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