P0242 — Turbocharger Boost Sensor B Circuit Low
Drive with caution — fix soon.
What P0242 means
This code means the voltage signal from turbocharger boost sensor B is lower than expected, usually pointing to a short to ground, a wiring fault, or a failed sensor. A disconnected or corroded connector can also cause it. It's a common turbo code and is typically fixed by repairing the wiring or replacing the boost sensor.
Common symptoms
- Check engine light is on
- Loss of power or weak acceleration
- Engine may enter reduced-power (limp) mode
- Increased fuel consumption
- Hesitation when accelerating
Common causes
- Faulty turbocharger boost sensor B
- Short to ground in the sensor signal wire
- Corroded or loose sensor connector
- Damaged or chafed wiring harness
- Open reference voltage circuit to the sensor
Typical repair cost
$100 – $400
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0242 code?
Short trips are usually fine, but the car may feel weak as it limits power for protection. Avoid hard acceleration and towing, and have it diagnosed soon.
How much does it cost to fix a P0242 code?
Usually $100 to $400. A straightforward sensor swap is cheaper, while tracking down a wiring short or harness damage adds labor.
Is a P0242 code serious?
It's moderate. You probably won't be stranded right away, but ongoing reduced power isn't ideal, so don't ignore it for long.
Does P0242 always mean a bad sensor?
No. A low signal can come from the sensor or from a wiring short to ground, a bad connector, or a missing reference voltage, so the circuit should be tested before replacing the sensor.