Block of codes
P25xx codes: turbo control
This block brings together the codes from P2500 to P2590 in the glossary. Open yours to see what it means, its causes and whether you can keep driving.
Reviewed by Daniel Morales, founder of Reprorace SL, on
What this block covers
Speed, idle and auxiliary inputs
The vehicle speed sensors and idle control, the speed the engine turns at when you are not accelerating.
Fuel and air metering
The engine measures the incoming air and meters the fuel so the mixture is right; the throttle, the accelerator pedal and the turbo are here too. A fault usually shows as higher fuel use, jerking, lack of power or hard starting.
Electrical system (12 V, starting and charging)
The battery, charging and the 12 V system and, on diesels, the glow plugs that help the engine start from cold.
Engine (mechanical, cooling and lubrication)
The engine's mechanics, timing (camshaft and crankshaft), cooling and lubrication. Many of these codes check that the engine is in time and at the right temperature.
Control modules and outputs
The car's control units and the reference voltages they feed their sensors with. Sometimes the fault is in the control unit; often it is in its power supply or wiring.
The 87 codes of the block
- P2500Generator lamp/L-terminal, circuit: signal low
- P2501Generator lamp/L-terminal, circuit: signal high
- P2502Charging system voltage: malfunction
- P2503Charging system voltage: too low
- P2504Charging system voltage: too high
- P2505ECM/PCM power input signal: malfunction
- P2506ECM/PCM power input signal: range/performance
- P2507ECM/PCM power input signal: signal low
- P2508ECM/PCM power input signal: signal high
- P2509ECM/PCM power input signal: intermittent
- P250AEngine oil level sensor, circuit: malfunction
- P250BEngine oil level sensor, circuit: range/performance
- P250CEngine oil level sensor, circuit: signal low
- P250EEngine oil level sensor, circuit: intermittent/erratic
- P250FEngine oil level: too low
- P2510ECM/PCM power relay, sense circuit: range/performance
- P2511ECM/PCM power relay, sense circuit: intermittent
- P2512Event data recorder, request circuit open
- P2513Event data recorder, request circuit: signal low
- P2514Event data recorder, request circuit: signal high
- P2515A/C refrigerant pressure sensor B, circuit: malfunction
- P2516A/C refrigerant pressure sensor B, circuit: range/performance
- P2517A/C refrigerant pressure sensor B, circuit: signal low
- P2518A/C refrigerant pressure sensor B, circuit: signal high
- P2519A/C request A, circuit: malfunction
- P2520A/C request A, circuit: signal low
- P2521A/C request A, circuit: signal high
- P2522A/C request B, circuit: malfunction
- P2523A/C request B, circuit: signal low
- P2524A/C request B, circuit: signal high
- P2525Vacuum reservoir pressure sensor, circuit: malfunction
- P2526Vacuum reservoir pressure sensor, circuit: range/performance
- P2527Vacuum reservoir pressure sensor, circuit: signal low
- P2528Vacuum reservoir pressure sensor, circuit: signal high
- P2529Vacuum reservoir pressure sensor, circuit: intermittent
- P252EEngine oil quality sensor, circuit: intermittent/erratic
- P252FEngine oil level: too high
- P2530Ignition switch run, position circuit: malfunction
- P2531Ignition switch run, position circuit: signal low
- P2532Ignition switch run, position circuit: signal high
- P2533Ignition switch on/start, position circuit: malfunction
- P2534Ignition switch on/start, position circuit: signal low
- P2535Ignition switch on/start, position circuit: signal high
- P2536Ignition switch accessory, position circuit: malfunction
- P2537Ignition switch accessory, position circuit: signal low
- P2538Ignition switch accessory, position circuit: signal high
- P2539Low pressure fuel system sensor, circuit: malfunction
- P253APTO, sense circuit open
- P253CPTO, sense circuit: signal low
- P253DPTO, sense circuit: signal high
- P253EPTO, sense circuit: intermittent/erratic
- P253FEngine oil: deteriorated
- P2540Low pressure fuel system sensor, circuit: range/performance
- P2541Low pressure fuel system sensor, circuit: signal low
- P2542Low pressure fuel system sensor, circuit: signal high
- P2544Torque management request input signal A: malfunction
- P2545Torque management request input signal A: range/performance
- P2546Torque management request input signal A: signal low
- P2547Torque management request input signal A: signal high
- P2548Torque management request input signal B: malfunction
- P2549Torque management request input signal B: range/performance
- P254APTO speed selector sensor/switch 1, circuit open
- P254BPTO speed selector sensor/switch 1: range/performance
- P254CPTO speed selector sensor/switch 1, circuit: signal low
- P2550Torque management request input signal B: signal low
- P2551Torque management request input signal B: signal high
- P2552Throttle/fuel inhibit A, circuit: malfunction
- P2553Throttle/fuel inhibit A, circuit: range/performance
- P2554Throttle/fuel inhibit A, circuit: signal low
- P2555Throttle/fuel inhibit A, circuit: signal high
- P2556Engine coolant level sensor/switch, circuit: malfunction
- P2557Engine coolant level sensor/switch, circuit: range/performance
- P2558Engine coolant level sensor/switch, circuit: signal low
- P2559Engine coolant level sensor/switch, circuit: signal high
- P255DPTO speed selector sensor/switch 2, circuit: signal high
- P255EPTO speed selector sensor/switch 2, circuit: intermittent/erratic
- P2560Engine coolant level: too low
- P2561A/C control module requested MIL illumination: malfunction
- P2562Turbocharger boost control position sensor A, circuit: malfunction
- P2563Turbocharger boost control position sensor A, circuit: range/performance
- P2564Turbocharger boost control position sensor A, circuit: signal low
- P2565Turbocharger boost control position sensor A, circuit: signal high
- P2566Turbocharger boost control position sensor A, circuit: intermittent
- P2586Turbocharger boost control position sensor B, circuit: malfunction
- P2588Turbocharger boost control position sensor B, circuit: signal low
- P2589Turbocharger boost control position sensor B, circuit: signal high
- P2590Turbocharger boost control position sensor B, circuit: intermittent/erratic
Other blocks
Read your car's fault codes on your phone
With an ECO-LITE in the OBD socket you see the codes in your account, with the data captured when the fault happened, and your workshop can check them remotely, always with your permission.
Keep reading
- OBD fault codes: what each one means
- Check engine light on: what to do
- How to read and clear your car's fault codes
- Will your car pass its MOT or inspection with the engine light on?
- Wi-Fi OBD2 reader: which one to choose
- Reading fault codes by car make
- Remote OBD diagnostics: what it is, how it works and what it can't do
- Vehicle diagnostics glossary