Fuel and air

P00F8 — Turbocharger Outlet Pressure Sensor A Circuit Malfunction

Severity: medium Drive with care, to a shop

What P00F8 means

The engine control module (ECM) compares the turbocharger outlet pressure sensor signal against the expected value and a valid voltage range. P00F8 sets when the signal from sensor A is missing, stuck, out of range or does not match engine operating conditions. Without accurate pressure data, the ECM cannot control boost properly.

Symptoms

  • Check Engine light on
  • Reduced power and sluggish acceleration
  • Delayed turbo response (turbo lag)
  • Poor fuel economy
  • Limp mode
  • Unusual noise from the turbo area

Possible causes

  1. Failed turbo outlet pressure sensor
  2. Open, damaged or corroded wiring or connector at the sensor
  3. Signal wire shorted to power or ground
  4. Charge-air leak downstream of the turbo: hoses, clamps, intercooler
  5. Faulty turbo actuator or variable geometry mechanism
  6. Rarely, ECM software or calibration issue

How to diagnose

  1. Scan all codes and freeze frame data and note the conditions when it set
  2. Inspect the sensor, connector and harness for chafing, heat damage, oil, moisture or corrosion
  3. Test sensor power, ground and signal with a multimeter using the factory wiring diagram
  4. Compare commanded and actual boost in live data
  5. Check intake hoses, clamps, intercooler and vacuum lines for leaks
  6. Check actuator movement over its full range
  7. Clear the code and road test to see if it returns

Common fixes

  • Repair the wiring or replace a damaged connector
  • Replace the turbo outlet pressure sensor
  • Fix boost leaks and replace damaged hoses
  • Repair or replace the turbo actuator or geometry mechanism
  • Update ECM software if the manufacturer confirms a fix

Questions and answers

Can I drive with a P00F8 code?

Only briefly and carefully, such as to a repair shop. Power is usually limited, and poor boost control can eventually harm the engine or turbo.

What most often causes P00F8?

Wiring or connector problems at the sensor are most common, followed by a failed sensor. Check the harness and boost leaks before replacing parts.

Is clearing the code enough?

No. If the cause remains, the code will return and the engine will keep running with reduced power.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.