Block of codes
P05xx codes: vehicle speed, idle control and auxiliary inputs
This block brings together the codes from P0500 to P0599 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.
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.
Emission control
The catalytic converter, oxygen sensors, EGR, fuel vapor system (EVAP), particulate filter and NOx reduction clean the exhaust. A fault here raises pollution and may make the car fail its inspection; left alone, some end in a bigger fault or in limp-home mode.
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.
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 125 codes of the block
- P0500Vehicle speed sensor A, circuit: malfunction
- P0501Vehicle speed sensor A, circuit: range/performance
- P0502Vehicle speed sensor A, circuit: signal low
- P0503Vehicle speed sensor A, circuit: intermittent, erratic or high
- P0504Brake switch A/B: correlation fault
- P0505Idle control system: malfunction
- P0506Idle control system RPM: lower than expected
- P0507Idle control system RPM: higher than expected
- P0508Idle air control system, circuit: signal low
- P0509Idle air control system, circuit: signal high
- P050ACold start idle control system: performance
- P050BCold start ignition timing: performance
- P050CCold start engine coolant temperature: performance
- P050DRough idle during cold start
- P050ECold start engine exhaust temperature: too low
- P050FBrake assist vacuum: too low
- P0510Closed throttle position switch: malfunction
- P0511Idle air, control circuit: malfunction
- P0512Starter, request circuit: malfunction
- P0513Incorrect immobilizer key: malfunction
- P0514Battery temperature sensor, circuit: range/performance
- P0515Battery temperature sensor, circuit: malfunction
- P0516Battery temperature sensor, circuit: signal low
- P0517Battery temperature sensor, circuit: signal high
- P0518Idle air, control circuit: intermittent
- P0519Idle air control system: performance
- P051ACrankcase pressure sensor A, circuit: malfunction
- P051BCrankcase pressure sensor A, circuit: range/performance
- P051CCrankcase pressure sensor A, circuit: signal low
- P051DCrankcase pressure sensor A, circuit: signal high
- P051ECrankcase pressure sensor A, circuit: intermittent/erratic
- P051FPCV filter: restriction
- P0520Engine oil pressure sensor/switch A, circuit: malfunction
- P0521Engine oil pressure sensor/switch A: range/performance
- P0522Engine oil pressure sensor/switch A: signal low
- P0523Engine oil pressure sensor/switch A: signal high
- P0524Engine oil pressure: too low
- P0525Cruise control servo, control circuit: range/performance
- P0526Fan speed sensor, circuit: malfunction
- P0527Fan speed sensor, circuit: range/performance
- P0528Fan speed sensor, circuit: no signal
- P0529Fan speed sensor, circuit: intermittent
- P052ACold start A camshaft position (bank 1): timing over-advanced
- P052BCold start A camshaft position (bank 1): timing over-retarded
- P052CCold start A camshaft position (bank 2): timing over-advanced
- P052DCold start A camshaft position (bank 2): timing over-retarded
- P052EPCV regulator valve: performance
- P0530A/C refrigerant pressure sensor A, circuit: malfunction
- P0531A/C refrigerant pressure sensor A, circuit: range/performance
- P0532A/C refrigerant pressure sensor A, circuit: signal low
- P0533A/C refrigerant pressure sensor A, circuit: signal high
- P0534A/C refrigerant: charge loss
- P0535A/C evaporator temperature sensor, circuit: malfunction
- P0536A/C evaporator temperature sensor, circuit: range/performance
- P0537A/C evaporator temperature sensor, circuit: signal low
- P0538A/C evaporator temperature sensor, circuit: signal high
- P0539A/C evaporator temperature sensor, circuit: intermittent
- P053APCV heater A, control circuit open
- P053BPCV heater A, control circuit: signal low
- P053CPCV heater A, control circuit: signal high
- P0540Intake air heater A, circuit: malfunction
- P0541Intake air heater A, circuit: signal low
- P0542Intake air heater A, circuit: signal high
- P0543Intake air heater A, circuit open
- P0544Exhaust gas temperature sensor (bank 1, sensor 1), circuit: malfunction
- P0545Exhaust gas temperature sensor (bank 1, sensor 1), circuit: signal low
- P0546Exhaust gas temperature sensor (bank 1, sensor 1), circuit: signal high
- P0547Exhaust gas temperature sensor (bank 2, sensor 1), circuit: malfunction
- P0548Exhaust gas temperature sensor (bank 2, sensor 1), circuit: signal low
- P0549Exhaust gas temperature sensor (bank 2, sensor 1), circuit: signal high
- P054ACold start B camshaft position (bank 1): timing over-advanced
- P054BCold start B camshaft position (bank 1): timing over-retarded
- P054CCold start B camshaft position (bank 2): timing over-advanced
- P054DCold start B camshaft position (bank 2): timing over-retarded
- P0550Power steering pressure sensor/switch, circuit: malfunction
- P0551Power steering pressure sensor/switch, circuit: range/performance
- P0552Power steering pressure sensor/switch, circuit: signal low
- P0553Power steering pressure sensor/switch, circuit: signal high
- P0554Power steering pressure sensor/switch, circuit: intermittent
- P0555Brake booster pressure sensor, circuit: malfunction
- P0556Brake booster pressure sensor, circuit: range/performance
- P0557Brake booster pressure sensor, circuit: signal low
- P0558Brake booster pressure sensor, circuit: signal high
- P0559Brake booster pressure sensor, circuit: intermittent
- P0560System voltage: malfunction
- P0561System voltage: unstable
- P0562System voltage: too low
- P0563System voltage: too high
- P0564Cruise control multi-function input A, circuit: malfunction
- P0565Cruise control on signal: malfunction
- P0567Cruise control resume signal: malfunction
- P0568Cruise control set signal: malfunction
- P0569Cruise control coast signal: malfunction
- P056ACruise control increase distance signal: malfunction
- P056BCruise control decrease distance signal: malfunction
- P0570Cruise control accelerate signal: malfunction
- P0571Brake switch A, circuit: malfunction
- P0572Brake switch A, circuit: signal low
- P0573Brake switch A, circuit: signal high
- P0574Cruise control system - vehicle speed: too high
- P0575Cruise control, input circuit: malfunction
- P0576Cruise control, input circuit: signal low
- P0577Cruise control, input circuit: signal high
- P0578Cruise control multi-function input A, circuit: stuck
- P0579Cruise control multi-function input A, circuit: range/performance
- P0580Cruise control multi-function input A, circuit: signal low
- P0581Cruise control multi-function input A, circuit: signal high
- P0582Cruise control vacuum, control circuit open
- P0583Cruise control vacuum, control circuit: signal low
- P0584Cruise control vacuum, control circuit: signal high
- P0585Cruise control multi-function input A/B: correlation fault
- P0586Cruise control vent, control circuit open
- P0587Cruise control vent, control circuit: signal low
- P0588Cruise control vent, control circuit: signal high
- P0589Cruise control multi-function input B, circuit: malfunction
- P0590Cruise control multi-function input B, circuit: stuck
- P0591Cruise control multi-function input B, circuit: range/performance
- P0592Cruise control multi-function input B, circuit: signal low
- P0593Cruise control multi-function input B, circuit: signal high
- P0594Cruise control servo, control circuit open
- P0595Cruise control servo, control circuit: signal low
- P0596Cruise control servo, control circuit: signal high
- P0597Thermostat heater, control circuit open
- P0598Thermostat heater, control circuit: signal low
- P0599Thermostat heater, control circuit: signal high
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