P0302 on Mercedes-Benz
Cylinder 2 Misfire Detected
P0302 on Mercedes-Benz vehicles indicates cylinder 2 misfire detected. Au7o has documented this code across 2 Mercedes-Benz models — most commonly on A-Class, GLB. This code means the engine computer has detected a misfire specifically in cylinder 2, meaning that cylinder isn't completing combustion properly on some firing events. The computer watches tiny variations in crankshaft speed to spot when a cylinder fails to fire, and a misfire means the air-fuel mixture isn't igniting correctly — usually from a spark, fuel, or compression problem in that cylinder. You may feel a stumble, rough idle, shaking, loss of power, or a flashing check-engine light, and persistent misfires can damage the catalytic converter. Because it names a single cylinder, the fault is often a component serving just cylinder 2, like its coil, plug, or injector. Typical repair costs on Mercedes-Benz range from $300 to $6,000, depending on the specific model and root cause.
Common Causes of P0302
- •Worn or fouled spark plug (cylinder 2)
- •Failed ignition coil or coil-on-plug (cylinder 2)
- •Clogged or faulty fuel injector (cylinder 2)
- •Vacuum or intake air leak affecting that cylinder
- •Low compression (worn rings, burnt/bent valve, head gasket)
- •Damaged spark plug wire or boot (if equipped)
- •Carbon-tracked or cracked coil/plug causing spark loss
- •Faulty PCM/ECM driver (rare)
P0302 on Mercedes-Benz by Model
Mercedes-Benz A-Class(1 issue)
- M282 1.3L Intake Valve Carbon Buildup2019-2023
The 1.3L turbocharged direct-injection M282 engine (co-developed with Renault, used in A180/A200) suffers carbon deposit buildup on the intake valves and ports because direct injection does not wash the valve backs with fuel. On urban/short-trip duty cycles deposits accumulate from roughly 60,000 miles, causing rough running and hesitation.
Mercedes-Benz GLB(1 issue)
- M260 Cylinder Head Exhaust Valve Seat/Guide Wear (Misfires, Compression Loss)2020-2022
The 2.0L turbo M260 four-cylinder used in the GLB 250 / GLB 35 (and the M264-related variants) suffers from premature wear of the exhaust valve seats and valve guides. The exhaust valves stop sealing, causing loss of compression in one or more cylinders, rough running and misfires. Mercedes acknowledged this as a manufacturing defect and issued a voluntary extended warranty in the US and Canada covering cylinder head replacement for up to 15 years / 150,000 miles on affected 2019-2022 A-Class, CLA, GLA and GLB vehicles. A 2026 NHTSA-posted TSB (MC-11028267) documents the valve seat/guide wear on M260/M264 engines. Left unaddressed it can progress to catastrophic piston/secondary damage that is NOT covered by the warranty extension.
Looking for P0302 on a different make?
View P0302 across all makes →Frequently Asked Questions
What does P0302 mean on Mercedes-Benz?▼
P0302 stands for "Cylinder 2 Misfire Detected." This code means the engine computer has detected a misfire specifically in cylinder 2, meaning that cylinder isn't completing combustion properly on some firing events. The computer watches tiny variations in crankshaft speed to spot when a cylinder fails to fire, and a misfire means the air-fuel mixture isn't igniting correctly — usually from a spark, fuel, or compression problem in that cylinder. You may feel a stumble, rough idle, shaking, loss of power, or a flashing check-engine light, and persistent misfires can damage the catalytic converter. Because it names a single cylinder, the fault is often a component serving just cylinder 2, like its coil, plug, or injector. On Mercedes-Benz specifically, this code is documented across 2 models.
What causes P0302 on Mercedes-Benz vehicles?▼
Common causes on Mercedes-Benz: Worn or fouled spark plug (cylinder 2), Failed ignition coil or coil-on-plug (cylinder 2), Clogged or faulty fuel injector (cylinder 2), Vacuum or intake air leak affecting that cylinder, Low compression (worn rings, burnt/bent valve, head gasket). Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0302 on a Mercedes-Benz?▼
Repair costs on Mercedes-Benz range from $300 to $6,000, depending on the specific model and root cause.
Which Mercedes-Benz models have P0302 documented?▼
Au7o has documented P0302 on 2 Mercedes-Benz models: A-Class, GLB.