OBD-II Trouble Codes: Meaning & Fixes

P0174 Powertrain The cylinder bank without cylinder 1 is running lean even with the maximum fuel correction… Moderate P0420 Powertrain The bank 1 catalytic converter no longer stores enough oxygen to clean the exhaust properly. Low B0001 Body The airbag module found a fault in the firing circuit for the driver's front airbag (stage 1). High C0035 Chassis The ABS module lost a valid signal from the driver-side front wheel speed sensor. Moderate P0101 Powertrain The MAF sensor's airflow reading doesn't match what the engine computer expects… Low P0113 Powertrain The intake air temperature signal is stuck at maximum voltage, which usually means an open… Low

P2101 Powertrain The throttle plate isn't reaching the position the computer asks for, fast enough or accurately… Moderate P2102 Powertrain Too little current or voltage reaches the throttle motor – usually resistance in the feed, not… Moderate P2103 Powertrain The throttle motor circuit draws too much current – a short, a shorted motor or a plate that… Moderate 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 P2106 Powertrain Reduced-power limp mode: the PCM caught a throttle or pedal fault – look for the companion code. Moderate P2107 Powertrain The processor supervising the electronic throttle failed its self-check – a computer fault, not… High P2108 Powertrain The throttle control module isn't performing as expected – check its power, data link… Moderate P2109 Powertrain The closed-throttle reading no longer matches what the computer learned – usually carbon… Low P2110 Powertrain The PCM is capping engine speed with fuel cut-off because it can't fully trust or close… Moderate 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 P2118 Powertrain The throttle motor is drawing more or less current than the PCM expects to hold the plate where… Moderate P2119 Powertrain The throttle plate isn't reaching the position the PCM commands, or won't spring back to its… Moderate P2120 Powertrain The PCM lost a usable signal from the main gas pedal sensor, often only for a moment. Moderate P2121 Powertrain The main gas pedal signal stays within normal voltage but moves in a way a real pedal can't. Moderate P2122 Powertrain The main gas pedal sensor reads close to 0 volts, below anything a working pedal produces… Moderate P2123 Powertrain The main gas pedal sensor reads near its full 5-volt supply or higher, even with your foot off… Moderate P2125 Powertrain The PCM lost a valid signal from the second, cross-check sensor in the gas pedal. Moderate P2127 Powertrain The second gas pedal sensor dropped below its minimum voltage, so the PCM can't verify pedal… Moderate P2128 Powertrain The second gas pedal sensor reads above its allowed maximum, so the pedal position can't be… Moderate P2135 Powertrain The two position signals inside the throttle body disagree, so the PCM can no longer trust… Moderate P2138 Powertrain The two sensors in the gas pedal report different pedal positions, so the PCM limits throttle… Moderate 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 P2176 Powertrain The PCM hasn't stored where the closed throttle sits, usually after a battery disconnect… Low P2177 Powertrain Bank 1 goes lean once the engine is above idle, so the PCM keeps adding fuel at cruise… Moderate P2178 Powertrain Above idle, bank 1 carries more fuel than the PCM asked for, and pulling fuel out no longer… Moderate P2181 Powertrain The engine isn't warming up or holding temperature the way the computer's model says it should. Low P2187 Powertrain Bank 1 runs lean at idle but recovers once rpm rises, the classic fingerprint of unmetered air. Low