Jeep OBD Codes: Meaning & Fixes

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 P0302 Powertrain Cylinder 2 keeps misfiring. On inline engines it's a middle cylinder, so rule out coolant… Moderate P0303 Powertrain Cylinder 3 is misfiring. Check whether it misses at idle or under load before you blame… Moderate P0304 Powertrain Cylinder 4 is misfiring. Its end or rear position makes water, oil and intake leaks common… Moderate P0335 Powertrain The engine computer lost the crankshaft position signal. Expect stalling or a crank-no-start. High

B1B02 Jeep · Body The airbag computer sees a break in the driver airbag's firing circuit, so it may not deploy… High C2200 Jeep · Chassis The ABS module found a fault in its own electronics and shut off ABS, traction and stability… Moderate C2217 Jeep · Chassis The electric power steering module found a fault inside itself and may reduce or cut steering… High P0105 Powertrain The PCM lost a usable signal from the manifold pressure sensor: dropouts, noise or values it… Moderate P0300 Powertrain The engine computer sees misfires that jump between cylinders or hit several cylinders at once. High P0302 Powertrain Cylinder 2 keeps misfiring. On inline engines it's a middle cylinder, so rule out coolant… Moderate P0303 Powertrain Cylinder 3 is misfiring. Check whether it misses at idle or under load before you blame… Moderate P0304 Powertrain Cylinder 4 is misfiring. Its end or rear position makes water, oil and intake leaks common… Moderate P0335 Powertrain The engine computer lost the crankshaft position signal. Expect stalling or a crank-no-start. High P0520 Powertrain The engine computer gets a signal from the oil pressure sensor or switch that makes no… Moderate P0521 Powertrain The oil pressure reading doesn't fit engine speed and temperature – a drifting sensor or truly… High P0622 Powertrain The alternator's field control or field feedback circuit is faulty – output may drop out… Moderate P0887 Powertrain The circuit that switches the transmission power relay reads high voltage when it shouldn't. Moderate P1391 Jeep · Powertrain The PCM keeps briefly losing the cam or crank position signal, which can make your Jeep stumble… Moderate P1698 Jeep · Powertrain The engine computer stopped hearing from the transmission computer, often leaving the Jeep… Moderate P2101 Powertrain The throttle plate isn't reaching the position the computer asks for, fast enough or accurately… Moderate P2138 Powertrain The two sensors in the gas pedal report different pedal positions, so the PCM limits throttle… Moderate P2503 Powertrain The alternator can't reach the voltage the ECM asks for – usually a worn alternator or slipping… Moderate P2504 Powertrain The charging system is overcharging – too much voltage can boil the battery and damage… High U0141 Network A body module labeled "A" went silent; on many trucks and SUVs it is the smart fuse box under… Moderate U0402 Network The transmission module is online, but the gear, range or torque data it sends doesn't add up. Moderate U0404 Network The electronic shifter reports a lever position the transmission can't trust, so Park may not… High