P0091 valve for fuel metering (N290) is set in the car computer. When there is malfunction in the fuel metering unit or in the ecu. P0091 valve for fuel metering unit, is the unit which control the flow of fuel in the high pressure pump and send the signal to the ecu. In modern vehicle fuel metering unit is use to regulate the fuel at higher pressure into the engine.Valve for metering unit play an important role in starting of engine. failure of the fuel metering unit can cause to not start the engine.
In some case low pressure of fuel in fuel supply system can cause this fault code. Because if fuel metering valve will not get enough pressure of fuel. Than also fault code will store in engine control module. Mechanical failure of high pressure pump or electrical failure of low pressure pump or fuel pump relay can be reason behind the fault code.
The fuel metering valve is power by a relay to the positive side and the ground is actuate by the ecu. in some case both positive and negative are controlled by ecu. On positive side there will be 12V from relay which is powering it. the signal from the metering valve increase as fuel pressure increase in the system. And decrease as fuel as fuel pressure decrease.
Cause of P0091 valve for fuel metering (N290) :
- A faulty valve for fuel metering unit.
- Faulty engine control module.
- Damage wiring from control module to metering valve.
- Low pressure of fuel in the system
Symptoms Of P0091 valve for fuel metering (N290) :
- Malfunction indicator lights on.
- Engine not starting problem.
- Also if starting then also not accelerating.
Solution of P0091 :
- Replace blown fuse or relay.
- Replace faulty metering valve.
- Repair faulty engine control module.
- replace electrical fuel pump.
- Change electrical fuel pump relay.
How to trouble shoot P0091 :
mechanic should start the diagnosis of this fault code by scaning the fault code. If fault code appear even after deleting that means fault code is permanent which have to be solve. Check the data streem of fuel low pressure pump, fuel high pressure pump, signal of fuel metering unit, and power supply of fuel metering unit from engine control module.
1) To solve this problem start from checking the fuel pressure in system after fuel filter. If the pressure of fuel in low pressure pump meat the proper value. 2) Then check fule pressure after high pressure pump. Mechanical failure of high pressure pump can also cause this fault code to store. If presure of fuel after high pressure pump does not meet the require value. Then it is quit possible to repair or replace the high pressure pump. 3) the next culprit of P0091 fault code is fuel metering unit it self failure of which can also cause this fault code to set in engine control module.
Most of the time fault code P0091 appear in control module because of low fuel pressure. That can be solve by repairing or replacing high pressure pump,Or fuel metering unit. In very rare cases fault code is associated by failure of engine control module.