P0239 Code: Turbocharger Boost Sensor B Circuit Malfunction
🟠 Moderate severity · drivable
Drivable, but the second boost reading is lost, which can reduce power — fix it soon.
What P0239 means
The computer detects an electrical fault, like an open or short, in the boost pressure sensor B circuit. Some turbo engines use a second boost sensor to check pressure in another spot, and a bad reading makes the computer limit power.
Symptoms
- Check engine light is on
- Loss of power
- Poor acceleration
- Possible limp mode
Common causes
- most common: Faulty boost pressure sensor
- common: Damaged or shorted sensor wiring
- common: Corroded or loose sensor connector
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Replace the boost pressure sensor | Yes | $50–150 |
| Clean and re-seat the sensor connector | Yes | $0–50 |
| Repair damaged sensor wiring | Mechanic | $50–150 |
Frequently asked questions
Can I drive with a P0239 code?
Yes, but power may be reduced because the computer can't read the second boost sensor. Fix it soon.
What is the most common cause of P0239?
A faulty boost pressure sensor, though wiring or connector problems are also common.
How much does it cost to fix a P0239?
Usually $50–150 for a new boost sensor, or less if cleaning the connector works.
Related codes
P0240
P0240 Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0241P0241 Code: Turbocharger Boost Sensor B Circuit Low Input
P0235P0235 Code: Turbocharger Boost Sensor A Circuit Malfunction
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.