Turbocharger outlet pressure sensor B is a second pressure sensor at a compressor outlet – for example one per turbo on twin-turbo engines or a second measuring point; sensor A has the codes P00F8–P00FC. It is a separate family from the boost pressure sensor: GM and Ford report the pressure ahead of the throttle under the boost sensor codes P0236–P0238. No manufacturer using the sensor B codes was found; FCA documents sensor A and a second outlet sensor. P01FF compares sensors A and B: with the engine off both should read barometric pressure, and in comparable operation they must agree within a tolerance. If they disagree without either being electrically faulty, this code sets; which one is wrong is found by comparing with barometric and manifold pressure. On twin-turbo engines a genuinely weaker turbo on one bank can also cause it.
Medium severity. Can I keep driving?Drive without demanding power and go to a repair shop soon. If you see a lot of blue smoke or hear a metallic noise, shut off the engine.
Symptoms
- Check engine light on
- Loss of power, boost limited
- Limp mode possible
Most likely causes
- One sensor drifting
- Leak or hose damage between the measuring points or on one bank
- Contact resistance at one sensor's connector or ground
- Uneven turbo output (twin-turbo, wastegate or vanes on one side)
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It can trigger limp mode.
- It affects emissions.
What each character of P01FF means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 1: Air and fuel
- FF: Specific fault in that system
Frequently asked questions
Can I keep driving with code P01FF?
Drive without demanding power and go to a repair shop soon. If you see a lot of blue smoke or hear a metallic noise, shut off the engine.
What causes code P01FF?
The most common causes are: one sensor drifting; leak or hose damage between the measuring points or on one bank; contact resistance at one sensor's connector or ground.
Related codes
- P00F8Turbocharger Outlet Pressure Sensor A Circuit
- P00F9Turbocharger Outlet Pressure Sensor A Range/Performance
- P01FATurbocharger Outlet Pressure Sensor B Circuit
- P01FBTurbocharger Outlet Pressure Sensor B Range/Performance
- P0236Turbocharger/Supercharger Boost Sensor A Circuit Range/Performance
Sources
- law.cornell.edu: 13 CCR 1968.2
- gsi.ext.gm.com: 18OBDG03A Engine Diagnostics
- static.nhtsa.gov: MC 10220897 9999
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.