P0300 on Genesis
Random/Multiple Cylinder Misfire Detected
P0300 on Genesis vehicles indicates random/multiple cylinder misfire detected. Au7o has documented this code across 1 Genesis model — most commonly on GV80. P0300 means the engine computer detected misfires occurring randomly or across multiple cylinders rather than in one specific cylinder. A misfire is when a cylinder fails to ignite its fuel-air mixture properly, which the computer senses through small fluctuations in crankshaft speed. Because it's not isolated to one cylinder, the cause is usually something that affects the whole engine — like fuel, air, or ignition system problems — rather than a single coil or plug. Persistent or heavy misfiring wastes fuel, runs rough, and can damage the catalytic converter, which is why a flashing check engine light should be taken seriously.
Common Causes of P0300
- •Worn or fouled spark plugs (across cylinders)
- •Vacuum or intake air leak
- •Weak fuel pump, clogged fuel filter, or low fuel pressure
- •Failing ignition coils or worn spark plug wires
- •Dirty or faulty mass airflow (MAF) sensor
- •Clogged or dirty fuel injectors
- •Faulty crankshaft/camshaft position sensor
- •Low compression or EGR/PCV system faults
P0300 on Genesis by Model
Genesis GV80(1 issue)
- 2.5L T-GDI Cold-Start Misfire P0300-P0304 (Service Campaign 914G / TSB 25-01-051G)2021-2024
Theta III 2.5L T-GDI engines in GV80 JX1 (and related G80/GV70) illuminate the Check Engine light with random or specific cylinder misfire codes P0300-P0304 during cold start. Root cause is identified as ECM misfire-detection logic; Genesis issued service campaign 914G covering 2021-2024MY GV80 built 07/27/2020-03/04/2024 for a free ECM reflash.
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View P0300 across all makes →Frequently Asked Questions
What does P0300 mean on Genesis?▼
P0300 stands for "Random/Multiple Cylinder Misfire Detected." P0300 means the engine computer detected misfires occurring randomly or across multiple cylinders rather than in one specific cylinder. A misfire is when a cylinder fails to ignite its fuel-air mixture properly, which the computer senses through small fluctuations in crankshaft speed. Because it's not isolated to one cylinder, the cause is usually something that affects the whole engine — like fuel, air, or ignition system problems — rather than a single coil or plug. Persistent or heavy misfiring wastes fuel, runs rough, and can damage the catalytic converter, which is why a flashing check engine light should be taken seriously. On Genesis specifically, this code is documented across 1 model.
What causes P0300 on Genesis vehicles?▼
Common causes on Genesis: Worn or fouled spark plugs (across cylinders), Vacuum or intake air leak, Weak fuel pump, clogged fuel filter, or low fuel pressure, Failing ignition coils or worn spark plug wires, Dirty or faulty mass airflow (MAF) sensor. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0300 on a Genesis?▼
Repair costs vary widely depending on the root cause and specific Genesis model.
Which Genesis models have P0300 documented?▼
Au7o has documented P0300 on 1 Genesis model: GV80.