P2539
Low Pressure Fuel System Sensor Circuit
- Severity
- High
- Driving
- Drive only to a garage
A fault in the low pressure fuel system sensor circuit. On a direct-injection engine there are two fuel pressures: a low-pressure lift pump feeds the tank fuel forward, and a high-pressure pump raises it to injection pressure. This sensor watches the first of those, and the high-pressure pump cannot work properly without it.
Possible causes
- CommonBlocked or overdue fuel filter
- CommonWorn or failing lift pump
- CommonFailed pressure sensor
- CommonCorroded connector or damaged wiring
- PossibleRestricted or kinked fuel line
- PossibleAir leak on the suction side of the fuel system
What you might notice
- Loss of power under load
- Hesitation at higher speeds
- Hard starting
- Cutting out
- Rough running
- Check engine light on
What to check, in order
- Check the fuel filter and when it was last changed. It is the cheapest thing here and a very common cause.
- Compare the reported low-side pressure with specification at idle and under load.
- Note when the symptom appears. A fault that only shows under load or at high speed is the classic signature of a supply that cannot keep up.
- Inspect the connector for corrosion and fuel contamination.
- Look for air leaks on the suction side - air drawn into the fuel makes pressure erratic and is easy to miss.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Vehicle speed control, idle control and auxiliary inputs
P2500P2501P2502P2503P2504P2505P2506P2507P2508P2509P2510P2511P2512P2513P2514P2515P2516P2517P2518P2519P2520P2521P2522P2523P2524P2525P2526P2527P2528P2529P2530P2531P2532P2533P2534P2535P2536P2537P2538P2539P2540P2541P2542P2543P2544P2545P2546P2547P2548P2549P2550P2551P2552P2553P2554P2555P2556P2557P2558P2559P2560P2561P2562P2563P2564P2565P2566P2567P2568P2569P2570P2571P2572P2573P2574P2575P2576P2577