P0237
UniversalTurbocharger/Supercharger Boost Sensor A Circuit Low: The Powertrain Control Module (PCM) has detected a voltage reading from the Turbocharger/Supercharger Boost Sensor A circuit that is lower than the specified range.
Medium SeverityThe Turbocharger/Supercharger Boost Sensor A is sending a signal to the engine computer (PCM) that is too low, indicating an issue with the sensor's circuit or the sensor itself. This can lead to noticeable reductions in engine power and fuel efficiency, and if not addressed, could potentially cause damage to the turbocharger system.
⚠️ Before You Begin (Safety First)
Always ensure the engine is completely off and cool before attempting any work on engine components. Disconnect the negative battery terminal to prevent accidental electrical shorts. Wear appropriate safety gear, including gloves and eye protection, to protect against hot surfaces and moving parts.
Common Symptoms
- Check Engine Light illuminated
- Reduced engine power or "limp mode"
- Poor acceleration
- Rough idling
- Decreased fuel economy
- Hesitation during acceleration
- Excessive exhaust smoke (less common but possible)
Common Causes
- Faulty Turbocharger/Supercharger Boost Sensor A
- Open or short circuit in the Boost Sensor A wiring harness
- Poor electrical connection at the sensor or the PCM
- Corrosion or damage to the sensor connector terminals
- Defective Powertrain Control Module (PCM) (rare)
Frequently reported on: 2010-2015 Ford F-150 (Ecoboost), 2008-2012 Subaru Impreza WRX/STI, 2007-2013 Audi A4/A5, 2014-2018 Chevrolet Cruze (1.4L Turbo), 2016-2020 Honda Civic (1.5L Turbo)
Diagnostic Steps
- Locate the Turbocharger/Supercharger Boost Sensor A on your vehicle (consult a repair manual for exact location).
- Visually inspect the sensor's wiring harness and connector for any signs of damage, fraying, corrosion, or loose connections. Repair as necessary.
- Using electrical contact cleaner, clean any visible corrosion from the sensor and harness terminals.
- If the wiring appears intact and secure, test the sensor's voltage and resistance using a multimeter, comparing readings to your vehicle's specifications.
- If the sensor tests faulty or if visual inspection indicates damage, replace the Turbocharger/Supercharger Boost Sensor A.
- Clear the P0237 DTC from the PCM using an OBD-II scanner and perform a test drive to confirm the repair.
👨🔧 When to Call a Professional
If, after carefully inspecting the wiring and connectors and potentially replacing the Boost Sensor A, the P0237 code persists, it's highly advisable to consult a professional mechanic. This could indicate a more complex electrical issue or even a rare PCM fault that requires specialized diagnostic tools.
Commonly Asked Questions
Can I continue driving with a P0237 code?
It is not recommended to drive for an extended period. Your engine will likely be in 'limp mode' with reduced power, and ignoring the issue could lead to more serious, costly damage to your turbocharger or engine.
What exactly is the 'Boost Sensor A'?
The Boost Sensor A (also known as a manifold absolute pressure or MAP sensor in some contexts) measures the pressure of the air entering your engine after the turbocharger. This information is crucial for the engine's computer to manage fuel delivery and ignition timing.
Is replacing the boost sensor a difficult DIY job?
The difficulty varies significantly by vehicle. On some cars, it's easily accessible; on others, it might require removing several other components. Always refer to your vehicle's specific repair manual for guidance.
Could a P0237 code be caused by something other than the sensor itself?
Yes, absolutely. Common causes include damaged or corroded wiring in the sensor's circuit, a poor electrical connection at the sensor or the engine's computer, or very rarely, a fault with the engine control module (PCM) itself.
Will simply clearing the code fix the problem?
Clearing the code will only turn off the Check Engine Light temporarily. If the underlying mechanical or electrical issue that triggered the P0237 code is not resolved, the code will inevitably return.