Check engine light on: Codes, Causes & Fixes

P0135 Powertrain The heater inside the upstream oxygen sensor on bank 1 isn't working or its circuit is faulty. Low P0174 Powertrain The cylinder bank without cylinder 1 is running lean even with the maximum fuel correction… Moderate P0300 Powertrain The engine computer sees misfires that jump between cylinders or hit several cylinders at once. High P0420 Powertrain The bank 1 catalytic converter no longer stores enough oxygen to clean the exhaust properly. Low P0430 Powertrain The bank 2 converter on a V6, V8 or split-exhaust engine isn't cleaning the exhaust well enough. Low P0101 Powertrain The MAF sensor's airflow reading doesn't match what the engine computer expects… Low

P0A93 Powertrain The inverter's separate coolant loop isn't carrying heat away – usually a dead electric… High P0A94 Powertrain A hybrid voltage converter isn't delivering the voltage it should – on Toyotas, the boost… High P0A95 Powertrain The main fuse in the high-voltage battery circuit has opened or its circuit reads open… Critical P0AA6 Powertrain High voltage is leaking toward the car body somewhere – an insulation fault that must be found… High P0AFA Powertrain Total high-voltage battery voltage dropped below the minimum the system allows, so power… High P1217 Nissan · Powertrain Nissan's ECM saw engine coolant get hotter than it should, usually because the radiator fan… Critical P1285 Ford · Powertrain Ford's cylinder head temperature sensor reports the engine is overheating. Pull over and shut… Critical P1295 Hyundai · Powertrain Hyundai's engine computer no longer trusts the electronic throttle and has cut power as… High P1299 Ford · Powertrain The engine got so hot that the Ford PCM is shutting off fuel to cylinders to save it. Stop… Critical P1340 Volkswagen · Powertrain The cam signal no longer lines up with the crank signal – often a jumped belt or stretched… High P1362 Honda · Powertrain The PCM gets no signal at all from the top dead center (TDC) sensor; stalling or a no-start… High P1682 Chevrolet · Powertrain The engine computer's two ignition power feeds disagree, which can cause stalling or Reduced… High P1778 Nissan · Powertrain The Jatco CVT's step motor is being commanded, but the pulley ratio isn't following it as it… High P17F0 Nissan · Powertrain The TCM detected judder it blames on the CVT itself, usually belt or pulley slip inside… High P2100 Powertrain The computer can't push current through the throttle motor – the circuit to the throttle body… High P2104 Powertrain A fail-safe has locked the engine at idle and the gas pedal no longer works – another code… High P2105 Powertrain The engine computer shut the engine off on purpose because it could no longer control… Critical P2107 Powertrain The processor supervising the electronic throttle failed its self-check – a computer fault, not… High P2111 Powertrain The throttle plate stayed more open than commanded – a real safety concern until you know why. High P2112 Powertrain The PCM asked the throttle to open, but it stayed shut – the engine can't get air, so it bogs… High P2146 Powertrain The shared power feed for one group of injectors is open, so every injector in that group has… High P2149 Powertrain The shared supply to the second injector group dropped out, often an intermittent wiring fault… High P2463 Powertrain The DPF is loaded with more soot than the ECU allows; it needs a regen or cleaning before it… High P246C Powertrain The DPF is so restricted that the ECM has cut engine power to protect the turbo, EGR system… High P2504 Powertrain The charging system is overcharging – too much voltage can boil the battery and damage… High P3000 Toyota · Powertrain Toyota's hybrid computer flags a fault in the high-voltage battery system and limits hybrid… High P3191 Toyota · Powertrain The hybrid system spun the gas engine with its motor-generator, but the engine never fired up. High U0001 Network A module found the high-speed CAN network itself misbehaving, not just one silent module. High U0073 Network A module saw so many errors on CAN bus A that it shut off its own transmitter. High U0100 Network Another module stopped hearing from the engine computer on the CAN network. High