Fuel and air

P01BF — Fuel Rail Pressure Sensor Range/Performance (Bank 2)

Severity: medium Drive with care, to a shop

What P01BF means

The engine control module constantly compares the bank 2 fuel rail pressure sensor signal with the commanded pressure and engine operating conditions. P01BF sets when the signal is out of range or does not behave as expected. The cause can be the sensor or its circuit, or a real fuel pressure problem.

Symptoms

  • Check Engine light on
  • Loss of power or hesitation
  • Rough idle or misfire
  • Poor fuel economy
  • Possible stalling
  • Hard starting or long cranking

Possible causes

  1. Faulty bank 2 fuel rail pressure sensor
  2. Damaged wiring or poor connector contact (open, short to ground or power)
  3. Low-pressure fuel supply problem: pump, filter, lines
  4. Worn or failing high-pressure fuel pump
  5. Faulty pressure regulator or volume control valve
  6. Excessive injector leakage (high return flow)
  7. Faulty ECM (rare)

How to diagnose

  1. Scan for codes and freeze frame data, and look for other fuel system codes
  2. Inspect the sensor connector and wiring for corrosion, chafing or heat damage
  3. Compare specified and actual rail pressure at cranking, idle and under load
  4. Check low-pressure supply pressure and volume first, and the filter condition
  5. Test sensor power, ground and signal with a multimeter or scope
  6. Check pressure regulator or volume control valve operation
  7. Measure injector return flow where applicable
  8. If everything checks out, test the ECM and its circuits

Common fixes

  • Replace the bank 2 fuel rail pressure sensor
  • Repair wiring or replace a damaged connector
  • Fix the supply fault: pump, filter or lines
  • Repair or replace the high-pressure pump, regulator or control valve
  • Replace injectors with excessive return flow
  • Diagnose and, if needed, replace or reprogram the ECM

Questions and answers

What does P01BF mean?

The ECM found that the bank 2 fuel rail pressure sensor signal is out of range or does not match what is expected. The cause may be the sensor, its wiring, or a real fuel pressure problem.

Can I drive with P01BF?

Only briefly and carefully, to a repair shop. The engine may lose power, misfire or stall, which can be dangerous in traffic.

Will replacing the sensor fix it?

Not always. Check the wiring and actual fuel pressure first, because a weak pump or faulty regulator will keep the code coming back even with a new sensor.

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.