P01FD

What it means

P01FD means the engine control unit has seen the signal from turbocharger outlet pressure sensor B sitting higher than the expected range, which points to an electrical fault in that sensor's circuit. The control unit sets the code when the sensor voltage is above the upper limit for a set period, or when it is implausible compared with other pressure readings. Sensor location and the exact definition of 'B' vary by model and engine, so check the manufacturer's data for your vehicle.

Symptoms

• Engine warning light on
• Reduced power or limp mode
• Poor or erratic turbo boost response
• Hesitation or surging under acceleration
• Possible black smoke or rough running under load
• Other boost or turbo related codes stored alongside

Possible causes

• Short to voltage or open circuit in the sensor signal wirelikely
• Faulty turbocharger outlet pressure sensor Blikely
• Damaged, corroded or loose sensor connector terminalslikely
• Open circuit or fault in the sensor ground or reference supplypossible
• Blocked or contaminated sensor port or pressure line (oil or soot build-up)possible
• Fault in the engine control unitrare
• Outdated or faulty control unit software where a manufacturer bulletin lists it as a known causerare

How to diagnose

1. Read all stored codes and freeze frame data, noting engine load, speed and boost at the time the fault set, and check for related sensor or turbo codes.
2. Look over the sensor, connector and wiring for chafing, heat damage, oil contamination, corrosion and bent or pushed-back pins.
3. With the ignition on and engine off, view live data for sensor B and compare it with the other pressure readings, such as barometric or intake manifold pressure; it should read close to ambient pressure.
4. Gently wiggle the harness and connector with the engine running or ignition on while watching live data for jumps or spikes.
5. Using the wiring diagram for the vehicle, check the sensor reference supply, ground and signal circuit for correct voltage, continuity, and shorts to voltage or to each other.
6. Remove the sensor and check the port and any connected pressure pipe for blockage, oil or soot build-up, and check the sensor for damage.
7. Check whether any manufacturer service bulletins or software updates relate to this code for the model and engine.
8. If the wiring and sensor test fine, have the control unit supply and signal circuits tested before considering it faulty.

How to fix

• Repair or replace damaged wiring, including any short to voltage or open circuit found.
• Clean or replace corroded or damaged connector terminals, or replace the connector.
• Replace the turbocharger outlet pressure sensor B if it fails testing or reads high with correct wiring.
• Clear blocked sensor ports or pressure lines and rectify the cause of oil or soot contamination.
• Update the control unit software only if the manufacturer lists an outdated calibration as a known cause for this fault.
• Repair or replace the control unit only after all other causes are ruled out and the fault is confirmed.

Can I keep driving?

Nearby codes

• P01FCGenericTurbocharger Outlet Pressure Sensor B Circuit Low
• P01FEGenericTurbocharger Outlet Pressure Sensor B Intermittent/Erratic