What it means
Generic electrical fault on turbocharger outlet pressure sensor B (second turbo or second measurement location).
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Turbocharger outlet pressure Sensor B measures pressure at the second designated turbo outlet sensing point or on the second turbo, depending on the system. The control module monitors its electrical signal and sets P01FA when it detects a general circuit fault, without this code alone identifying the specific electrical failure.
Common causes
Most likely first.
- Turbocharger outlet pressure sensor failure
- Damaged wiring or loose connector
- Blocked or leaking pressure-sensing hose
- Poor sensor power or ground connection
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
- Use a scan tool to capture freeze-frame data and compare Sensor B pressure data with Sensor A and other relevant pressure readings.
- Inspect Sensor B's connector and harness for loose or corroded terminals, damaged insulation, or contact with hot or moving parts.
- Check the pressure-sensing hose or passage for disconnection, blockage, leaks, or damage.
- Test Sensor B's supply, ground, and signal circuit for opens, shorts, or poor connections against the manufacturer's specification.
- If the circuit and pressure path are sound, test Sensor B itself and check for air-path leaks that could explain abnormal readings.
Common fixes
- Reconnect or replace a leaking, blocked, or damaged Sensor B pressure hose.
- Repair damaged wiring or clean and secure the Sensor B connector.
- Repair an air-path leak found during inspection.
- Replace turbocharger outlet pressure Sensor B if it fails circuit and plausibility checks.
Can I keep driving?
Avoid hard acceleration and towing until the fault is diagnosed, especially if power drops or the engine enters a reduced-power mode. Stop if smoke, unusual turbo noise, or severe power loss develops, as continued operation could worsen an air-path or turbo-related problem.
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.