P0087: Fuel rail/system pressure too low
The fuel pressure is lower than the engine computer asks for. The engine may lose power, go into limp mode or stall.
Updated
What P0087 means
Mostly on diesels with common-rail injection and petrol engines with direct injection, a pump in the tank feeds a high-pressure pump on the engine, which fills the fuel rail that supplies the injectors. A sensor on the rail reports the pressure, and the engine computer controls it.
When the measured pressure stays below what the computer asks for, it stores P0087, and often limits the power.
P0088 to P0092: pressure too high, and the pressure regulator
P0088 is the opposite: the pressure is higher than the engine computer asks for, often because the regulator or control valve sticks, or the pressure sensor reads too high. P0089 means the pressure doesn’t follow the regulator’s commands; P0090, P0091 and P0092 mean a fault in the regulator’s electrical circuit (open, low or high).
The urgency is the same as for P0087: the engine computer often limits the power, and the engine can start badly or stall. A fuel leak found by the engine computer has its own code, P0093, and needs you to stop.
P0088: Fuel rail/system pressure too high
The fuel pressure is higher than the engine computer asks for. The engine may run rich, lose power or go into limp mode.
Common causes: fuel pressure regulator or control valve stuck, faulty fuel pressure sensor reading too high, blocked or kinked fuel return line.
P0089: Fuel Pressure Regulator A Performance
The fuel pressure doesn’t follow what the engine computer asks the pressure regulator or control valve for. The engine may lose power, go into limp mode or start badly.
Common causes: worn or sticking fuel pressure regulator or control valve, weak supply from the tank pump, or a clogged fuel filter, faulty fuel pressure sensor, worn high-pressure fuel pump.
P0090: Fuel Pressure Regulator A Control Circuit/Open
The engine computer has found a fault in the electrical circuit of the fuel pressure regulator or control valve, so it can’t control the fuel pressure properly. The engine may go into limp mode, start badly or stall.
Common causes: faulty fuel pressure regulator or control valve, wiring or connector fault, such as corrosion, blown fuse or poor earth, fault in the engine computer (rare).
P0091: Fuel Pressure Regulator A Control Circuit Low
The engine computer has found a fault in the electrical circuit of the fuel pressure regulator or control valve, so it can’t control the fuel pressure properly. The engine may go into limp mode, start badly or stall.
Common causes: faulty fuel pressure regulator or control valve, wiring or connector fault, such as corrosion, blown fuse or poor earth, fault in the engine computer (rare).
P0092: Fuel Pressure Regulator A Control Circuit High
The engine computer has found a fault in the electrical circuit of the fuel pressure regulator or control valve, so it can’t control the fuel pressure properly. The engine may go into limp mode, start badly or stall.
Common causes: faulty fuel pressure regulator or control valve, wiring or connector fault, such as corrosion, blown fuse or poor earth, fault in the engine computer (rare).
Can I keep driving?
Drive gently
Drive gently and have it checked soon. The engine can lose power or stall, so avoid motorways and overtaking until it’s fixed. If you smell fuel, stop when it’s safe to do so and don’t restart the engine.
General guidance based on the code alone, not on the car’s actual condition. If in doubt, stop and ask a mechanic.
Low fuel pressure can make the engine lose power suddenly, especially when accelerating or climbing. On a diesel that ran out of fuel, the system may need bleeding before it runs properly again.
Symptoms
- Less power, or limp mode.
- Hesitation or jerking under load.
- Long cranking or hard starting.
- Stalling on some cars.
Common causes
- Clogged fuel filter. It starves the pumps, most noticeably under load. On many diesels it’s a service item that’s easy to overlook.
- Weak or failing fuel pump. Either the pump in the tank or the high-pressure pump on the engine.
- Faulty fuel pressure sensor or regulator. A sensor that reads low, or a regulator that lets the pressure go, sets the same code.
- Fuel leak, or a very low fuel level. Running the tank nearly empty can let the pump draw air. A leak is a fire risk.
Typical fixes
- Fill up, and check for a smell of fuel or wet patches. If you find a leak, don’t drive.
- Replace the fuel filter if it’s due or its condition is unknown.
- Have the requested and actual rail pressure compared with a diagnostic tool, and the supply from the tank pump tested.
- Have the high-pressure pump, the regulator and the rail pressure sensor checked if the supply is fine.
Questions
Can I drive with P0087?
Gently, and have it checked soon. The engine can lose power or stall, so avoid motorways and overtaking until it’s fixed. If you smell fuel, stop when it’s safe to do so and don’t restart the engine.
Can a clogged fuel filter cause P0087?
Yes, it’s one of the usual causes, and one of the easiest to fix. If the code comes back with a new filter, have the pumps and the pressure sensor checked.