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

P0157 Powertrain The O2 sensor after the bank 2 converter reads near zero volts – often a nearby exhaust leak… Low P0158 Powertrain The O2 sensor after the bank 2 converter reads too high – often a short to heater power… Low P0161 Powertrain The heater in the O2 sensor behind the bank 2 converter isn't working, or its under-car wiring… Minor P0170 Powertrain Bank 1 fuel correction is far outside its normal window, lean or rich, and the ECU won't say… Moderate P0171 Powertrain The engine computer is adding the maximum extra fuel it's allowed on bank 1 and still sees… Moderate P0172 Powertrain The engine computer is pulling as much fuel as it's allowed on bank 1 and the mixture is still… Moderate P0173 Powertrain Fuel correction on bank 2, the side without cylinder 1, is out of range or unstable, lean… Moderate P0174 Powertrain The cylinder bank without cylinder 1 is running lean even with the maximum fuel correction… Moderate P0175 Powertrain Bank 2 is still running rich even though the PCM is already cutting fuel on that side as far as… Moderate P0181 Powertrain The fuel temperature reading is electrically fine but doesn't match the engine's other… Low P0182 Powertrain The fuel temperature signal is pulled close to 0 V, so the engine computer thinks the fuel… Low P0183 Powertrain The fuel temperature signal sits near 5 V, as if the sensor were unplugged; the PCM reads… Low P0190 Powertrain The signal from the fuel rail pressure sensor has dropped out or become unusable to the engine… Moderate P0191 Powertrain The rail pressure reading is electrically valid but doesn't make sense for how the engine… Moderate P0192 Powertrain The rail pressure sensor signal voltage has fallen below the lowest value a working sensor can… Moderate P0193 Powertrain The rail pressure sensor signal is stuck near the 5-volt limit, above anything a working sensor… Moderate P0200 Powertrain The ECU found a fault in the injector control circuits that it can't pin on one cylinder, often… High P0201 Powertrain The ECU sees an open or faulty electrical circuit to injector 1, so cylinder 1 is probably… Moderate P0202 Powertrain Injector 2's circuit is open or out of range; on an inline-four it's a middle cylinder under… Moderate P0203 Powertrain The ECU sees no normal electrical response from injector 3: its coil, its wiring or its driver… Moderate P0204 Powertrain The circuit to injector 4 is open or out of range; on most transverse engines that's… Moderate P0205 Powertrain The ECU sees a broken or faulty electrical circuit to the cylinder 5 injector, so that cylinder… Moderate P0206 Powertrain Injector 6's circuit is open or faulty. On an inline-six that's the rear cylinder, tucked under… Moderate P0207 Powertrain The ECU lost normal control of injector 7, which only exists on V8 and larger engines. Moderate P0208 Powertrain The circuit to injector 8, the rear cylinder on bank 2 of a V8, is open or doesn't respond… Moderate P0216 Powertrain The ECU can't control or confirm injection timing, usually on a diesel with an electronic… High P0217 Powertrain The engine overheated. Stop driving: continuing can warp the head, blow the head gasket… Critical P0218 Powertrain The transmission fluid got hotter than the computer allows, from heavy load, low fluid… High P0219 Powertrain The engine was spun faster than its maximum allowed rpm, usually by a missed shift or wheelspin. Moderate P0221 Powertrain The second throttle angle signal leaves its window or stops following the plate, so power… Moderate