P0242 moderate

Turbo/Supercharger Boost Sensor B Circuit High (Bank 2)

The P0242 code means the vehicle's onboard diagnostic system has detected: Turbo/Supercharger Boost Sensor B Circuit High (Bank 2). This is a moderate severity code.

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Keep driving?
Short distances only
DIY difficulty
moderate
Estimated cost
$80 - $400 (parts and labor)
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Common Symptoms

  • Check Engine Light on
  • Bank 2 turbo boost limited
  • Engine may enter limp mode
  • Uneven power delivery

Probable Causes (Ranked by Likelihood)

  • Open circuit in Bank 2 boost sensor wiring Very High
  • Failed Bank 2 boost sensor (open) High
  • Disconnected sensor connector Moderate
  • Short to reference voltage Low

Step-by-Step Diagnostic Procedure

  1. Read Bank 2 boost sensor voltage. Above 4.8V at key-on engine-off confirms high circuit.

  2. Verify connector is fully connected and seated.

  3. Test wiring continuity from sensor to PCM.

  4. Inspect for chafing between signal and reference wires.

Frequently Asked Questions

What causes a high circuit on Bank 2 boost sensor?

An open wire or disconnected connector causes the signal to float to the reference voltage. The sensor itself may also have an internal open.

Can this be caused during maintenance?

Yes, if the boost sensor connector was not reconnected after intake work, P0242 will set immediately.

Is this code related to overboosting?

No, P0242 is a sensor circuit fault. Actual overboost would set P0234 or similar mechanical overboost codes.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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