Honda 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 P0430 Powertrain The bank 2 converter on a V6, V8 or split-exhaust engine isn't cleaning the exhaust well enough. Low P0172 Powertrain The engine computer is pulling as much fuel as it's allowed on bank 1 and the mixture is still… Moderate 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

P0012 Powertrain The bank 1 intake cam lags behind the angle the PCM wants, often from chain stretch or weak oil… Moderate P0087 Powertrain Measured fuel pressure has dropped well below what the engine computer is asking for. High P0152 Powertrain Bank 2's front O2 sensor is pinned high – usually voltage leaking in from its heater wire… Moderate P0172 Powertrain The engine computer is pulling as much fuel as it's allowed on bank 1 and the mixture is still… Moderate P0300 Powertrain The engine computer sees misfires that jump between cylinders or hit several cylinders at once. High P0301 Powertrain Cylinder 1 is repeatedly failing to fire. The cause is almost always its coil, plug, injector… Moderate 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 P0720 Powertrain Electrical fault in the output shaft speed signal – shift timing and sometimes the speedometer… Moderate P0733 Powertrain Third gear slips: input shaft speed doesn't match output speed times the 3rd-gear ratio. Moderate P0735 Powertrain Fifth gear slips or isn't fully applied; the TCM measures a ratio that doesn't fit 5th. Moderate P0741 Powertrain The torque converter lockup clutch slips or won't engage when the computer commands it. Moderate P0751 Powertrain Solenoid A is wired fine but its valve isn't doing its job, so gears are missing – often stuck… High P0753 Powertrain The control circuit for shift solenoid A reads open, shorted or out of range – an electrical… Moderate P0776 Powertrain Pressure control solenoid B isn't delivering the pressure the TCM asks for – harsh or slipping… Moderate P0780 Powertrain A gear change didn't complete the way the TCM expected, but it can't pin the fault to one part. Moderate P1259 Honda · Powertrain The PCM saw the VTEC solenoid or VTEC oil pressure switch misbehave on an older Honda VTEC… Moderate P1361 Honda · Powertrain The top dead center (TDC) sensor signal keeps dropping out for a moment while the engine… Moderate P1362 Honda · Powertrain The PCM gets no signal at all from the top dead center (TDC) sensor; stalling or a no-start… High P1399 Honda · Powertrain An older Honda's PCM counted misfires that jump between cylinders instead of staying in one. Moderate P1519 Honda · Powertrain The PCM found a fault in the idle air control valve (IACV) circuit on a Honda with a cable… Moderate P1607 Honda · Powertrain The Honda engine computer's self-test found a fault inside its own circuitry. Moderate P2178 Powertrain Above idle, bank 1 carries more fuel than the PCM asked for, and pulling fuel out no longer… Moderate P219A Powertrain One cylinder on bank 1 runs clearly richer or leaner than the others, even if the average looks… Moderate P219B Powertrain One cylinder on bank 2 runs off the mixture of the other cylinders on that side of the engine. Moderate P2647 Powertrain The VTEC oil pressure switch reports the high-lift rockers engaged while the engine computer… Moderate P3400 Powertrain Cylinder shut-off on bank 1 (AFM, DFM, MDS or VCM) isn't doing what the engine computer… Moderate P3497 Honda · Powertrain Honda's Variable Cylinder Management on the front cylinder bank didn't behave the way the PCM… Moderate