OBD-II Trouble Codes: Meaning & Fixes

C0035 Chassis The ABS module lost a valid signal from the driver-side front wheel speed sensor. Moderate P0135 Powertrain The heater inside the upstream oxygen sensor on bank 1 isn't working or its circuit is faulty. Low B0001 Body The airbag module found a fault in the firing circuit for the driver's front airbag (stage 1). High P0171 Powertrain The engine computer is adding the maximum extra fuel it's allowed on bank 1 and still sees… Moderate P0420 Powertrain The bank 1 catalytic converter no longer stores enough oxygen to clean the exhaust properly. Low P0128 Powertrain The engine takes too long to warm up, which almost always points to a thermostat stuck open. Low

P0884 Powertrain The transmission computer's power supply dropped out briefly – usually a battery, ground… Moderate P0887 Powertrain The circuit that switches the transmission power relay reads high voltage when it shouldn't. Moderate P0894 Powertrain The transmission computer measured slip inside the gearbox that shouldn't be there. Clutches… High P090C Ford · Powertrain The PowerShift TCM sees a low signal on the motor that works clutch B, the even-gear… Moderate P0A0F Powertrain The hybrid system spun the gas engine with its motor-generator to start it, but the engine… High P0A1F Powertrain The module that manages the high-voltage battery failed its self-check or reports implausible… Moderate P0A7E Powertrain The high-voltage battery got too hot. A clogged cooling intake or dirty fan is the usual cause. Moderate P0A7F Powertrain The battery computer has calculated that the whole high-voltage pack has worn past its usable… Moderate P0A80 Powertrain The hybrid system sees weak or unbalanced modules in the high-voltage battery and flags… Moderate 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 P1128 Volkswagen · Powertrain VW's part-load fuel adaptation has maxed out adding fuel on bank 1 – the engine runs lean as… Moderate P1217 Nissan · Powertrain Nissan's ECM saw engine coolant get hotter than it should, usually because the radiator fan… Critical P1233 Ford · Powertrain The Ford PCM lost the status signal from the fuel pump driver module, so fuel pump control… Moderate P1259 Honda · Powertrain The PCM saw the VTEC solenoid or VTEC oil pressure switch misbehave on an older Honda VTEC… Moderate P1260 Ford · Powertrain Ford's Passive Anti-Theft System didn't accept the key, so the PCM shut off fuel and the engine… Moderate P1272 Nissan · Powertrain The front air/fuel ratio sensor on bank 1 isn't sending a usable, moving signal to the Nissan… Moderate P1285 Ford · Powertrain Ford's cylinder head temperature sensor reports the engine is overheating. Pull over and shut… Critical P1289 Ford · Powertrain The CHT sensor signal on your Ford is stuck near 5 volts, which the PCM reads as an impossibly… Moderate P1295 Hyundai · Powertrain Hyundai's engine computer no longer trusts the electronic throttle and has cut power as… High P1297 Volkswagen · Powertrain Boost is escaping between turbo and throttle body – usually a split hose or a leaking diverter… Moderate P1299 Ford · Powertrain The engine got so hot that the Ford PCM is shutting off fuel to cylinders to save it. Stop… Critical P1300 Toyota · Powertrain Toyota's ECM fires ignition coil No. 1 but gets no confirmation pulse (IGF) back from its… Moderate P1305 Toyota · Powertrain The igniter in Toyota coil No. 2 stops confirming its sparks, often only once the engine is hot. Moderate P1310 Toyota · Powertrain No spark confirmation from one Toyota coil: No. 3 on four-cylinders, but a different coil… Moderate P1320 Nissan · Powertrain The Nissan ECM isn't seeing the ignition primary signal it expects while the engine cranks… Moderate P1326 Hyundai · Powertrain Hyundai's KSDS software heard vibration typical of worn rod bearings and put the engine in limp… Critical