What it means
The turbocharger speed sensor B circuit has a fault. This code does not by itself identify the sensor location or prove that the vehicle has a second turbocharger.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Turbocharger speed sensor B provides a signal the engine control module uses to monitor turbocharger speed. This circuit code indicates a fault in that signal path, such as an open or shorted wire, failed sensor, or damaged target; it does not establish where sensor B is located or mean the vehicle has two turbochargers.
Common causes
Most likely first.
- Open or shorted wiring or connector at the turbocharger speed sensor
- Failed turbocharger speed sensor
- Damaged sensor reluctor or target wheel
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
How to diagnose it
- Review freeze-frame data and live turbo-speed readings, including sensor B, for missing or implausible data during the fault.
- Inspect sensor B's connector and harness near the turbocharger for loose pins, heat damage, oil, or chafing.
- Check the sensor and connector for physical damage and confirm the sensor is securely mounted.
- Test sensor B's supply, ground, and signal wiring for opens or shorts according to the manufacturer's procedure.
- If the circuit tests correctly, test the sensor and inspect its target or reluctor for damage.
Common fixes
- Secure the sensor B connector and repair damaged terminals.
- Repair an open, shorted, or heat-damaged section of sensor wiring.
- Replace turbocharger speed sensor B if it fails circuit and signal tests.
- Repair a damaged sensor target or reluctor if inspection confirms it is the source of the fault.
Can I keep driving?
This fault can affect boost control and may be accompanied by substantial power loss or limp mode. Avoid heavy acceleration and stop if smoke, unusual turbo noise, or severe power loss develops; arrange diagnosis promptly.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.