P0242Turbocharger/Supercharger Boost Sensor B Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- Boost sensor B is a second boost pressure sensor, for a second turbo or bank on parallel twin-turbo engines or a second stage on two-stage systems. No manufacturer using sensor B codes was found – GM, Ford and Saab, even on two-stage and twin-turbo engines, use a single boost sensor; the description follows CARB and the documented sensor A codes. P0242 means the signal of sensor B is above its upper limit – for sensor A, GM uses 86 % of 5 V and Ford 4.88 V for 5 s. Causes are a short to voltage, an open ground or, on a pulled-up input, an open signal wire.
- What you may notice
- Check engine light on
- Loss of power, limp mode
- Boost B shows its maximum value
- Likely causes
- LikelySensor ground open, or signal wire open on a pulled-up input
- PossibleSignal shorted to 5 V or 12 V
- PossibleSensor faulty internally
- RareEngine module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €30 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.