P0087
Fuel Rail/System Pressure - Too Low Bank 1.
- Generic
- Powertrain
- Generic code
- High severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- 0
- AreaFuel and air metering, auxiliary emission controls
- 87
- FaultThe specific fault in that area
What it means
P0087 means the engine control unit has seen the fuel rail pressure sit below the target value for longer than it allows. The pressure sensor reading was lower than the commanded pressure, so the system is not delivering enough fuel at the required pressure. It applies to petrol direct injection and diesel common rail systems, and the exact pressure strategy depends on the engine.
Symptoms
- Engine warning light on, often with limp mode or reduced power
- Long cranking or hard starting, especially when hot
- Hesitation, flat spots or poor acceleration under load
- Rough idle, misfires or stalling
- Engine cutting out when pulling away or at high load
Possible causes
- Clogged or restricted fuel filter or blocked in-tank pickup or strainerlikely
- Weak low-pressure fuel pump or faulty pump supply voltage or relaylikely
- Worn or failing high-pressure fuel pump, or a faulty pressure control or metering valvelikely
- Leaking or stuck-open injector, or a leaking pressure regulator or relief valvepossible
- Fuel rail pressure sensor giving a false low reading, or related wiring or connector faultpossible
- Low fuel level, poor quality or contaminated fuel, or air in the fuel systempossible
- Fuel leak on the high-pressure or low-pressure side, or a split return linerare
How to diagnose
- Read all stored and pending codes and the freeze frame data to see engine load, speed, temperature and the commanded versus actual rail pressure when it set.
- Check the fuel level and the fuel quality, and ask when the filter was last changed.
- Visually inspect the fuel lines, rail, injectors and pump area for leaks, damage or fuel smell, and check wiring and connectors to the pump, sensor and pressure valve.
- Check the fuel pump fuse, relay and supply voltage and earth while the pump is running.
- Watch live rail pressure against the target at idle, under load and during cranking, and compare the sensor reading with a known good reference where the manufacturer provides one.
- Measure low-pressure supply pressure and volume against the manufacturer specification before suspecting the high-pressure pump.
- Test the pressure control valve operation and injector return flow or leak-off where the engine design allows, following the manufacturer procedure.
- Check for other fault codes such as sensor or misfire codes that may point to the root cause.
How to fix
- Replace the fuel filter and clean or replace a blocked pickup strainer, then clear any water or contamination from the system.
- Repair the pump wiring, relay or supply voltage fault, or replace the low-pressure fuel pump.
- Replace the high-pressure pump or pressure control valve if testing shows it cannot reach target pressure.
- Replace leaking or faulty injectors or the pressure regulator, following the manufacturer procedure for the engine.
- Replace the rail pressure sensor or repair its wiring if the reading is false.
- Repair any fuel leaks and bleed the system, then clear the code and road test to confirm.
Can I keep driving?
Avoid driving until it is checked, as the engine can lose power or stall without warning, which is unsafe in traffic. Low fuel pressure can also cause lean running and damage the fuel system, so keep any short trip to a minimum.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.