OBD-II Generic Error Code P0242: How to Fix It
Medium 1-2 hours Medium Severity
Verified June 2026
- Error Code
- P0242
- Brand
- OBD-II Generic
- Product Type
- automotive
- Severity
- Medium
- DIY Difficulty
- Medium
- Estimated Fix Time
- 1-2 hours
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Tools You'll Need
- OBD2 scanner
- Digital multimeter
- Basic hand tools (screwdrivers, sockets)
- Vehicle service manual (for wiring diagrams)
How to Fix Error Code P0242
-
Check for Other Codes and Freeze Frame Data
Ensure the ignition is off when connecting the scanner. -
Inspect the Boost Pressure Sensor B and Wiring
Allow the engine to cool before working near the turbocharger. -
Test the Boost Sensor Voltage
Be careful not to short the multimeter probes. -
Check the Sensor Ground and Reference Voltage
Do not pierce wires unless necessary; use back-probing pins. -
Replace the Boost Pressure Sensor B
Use sensor-safe dielectric grease on connectors if recommended. -
Inspect the Turbocharger and Vacuum Lines
Turbocharger components can be hot; let engine cool completely.
Parts You May Need
Boost Pressure Sensor B
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Dielectric grease
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Boost Pressure Sensor B
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Dielectric grease
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Boost Pressure Sensor B
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Dielectric grease
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Boost Pressure Sensor B
Check Price on Amazon
Dielectric grease
Check Price on Amazon
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When to Call a Professional
If after replacing the sensor and checking wiring the code returns, or if you suspect internal engine or turbocharger damage, seek professional diagnosis. A mechanic can perform boost pressure tests and smoke leak tests.Frequently Asked Questions
What does OBD-II code P0242 mean?
P0242 means the ECM detected a high voltage signal from the turbocharger boost pressure sensor B, indicating an electrical problem or sensor fault.
Can I drive with error code P0242?
You can drive short distances, but the engine may enter limp mode, reducing power. Prolonged driving can cause further damage.
How much does it cost to fix P0242?
DIY cost is around $50-$150 for a new sensor. Professional repair can range from $200 to $500 including diagnosis and labor.
What is the difference between boost sensor A and B?
They are similar sensors monitoring different points in the intake system. Codes refer to specific sensor locations (A vs B).
How do I reset code P0242 after repair?
Use an OBD2 scanner to clear the code, or disconnect the battery for 10 minutes. The code will return if the problem persists.