P0300 on Mercedes-Benz GLC: Fix & DLC Location
Factory diagnostic troubleshooting wire for fault code P0300 (P0300: Random or Multiple Cylinder Misfire Detected) specifically on the Mercedes-Benz GLC (2020–2026, 2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC).
1. Symptoms of P0300 on Mercedes-Benz GLC
When the Engine Control Module (ECM/PCM) on your Mercedes-Benz GLC (2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC) logs fault code P0300, drivers commonly observe:
2. Most Likely Causes on Mercedes-Benz GLC
Historical warranty claims and technical repair bulletins for Mercedes-Benz GLC point to the following failure distribution:
3. Step-by-Step DIY Repair Guide for Mercedes-Benz GLC
Plug a handheld OBD-II scanner into the 16-pin port under the dashboard. Check if specific cylinder codes like P0301 (Cylinder 1) or P0304 (Cylinder 4) accompany P0300. on the Mercedes-Benz GLC equipped with 2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC.
Remove the ignition coils, use a spark plug socket with ratchet to unthread spark plugs. Inspect electrode tips for carbon buildup, oil fouling, or burnt gaps. Replace with OEM iridium plugs gapped to spec. on the Mercedes-Benz GLC equipped with 2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC.
Perform an ignition swap test: Swap coil from a suspected misfiring cylinder to an adjacent cylinder. Clear codes and re-scan. If the misfire moves, replace the faulty coil. on the Mercedes-Benz GLC equipped with 2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC.
Inspect PCV hoses, intake boot, and vacuum lines for cracking or hissing sounds while engine idles. Smoke test the intake if necessary. on the Mercedes-Benz GLC equipped with 2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC.
Add a bottle of premium fuel injector cleaner (e.g. Chevron Techron). Clear the OBD-II codes with your scanner and take the car on a 15-minute drive cycle to confirm readiness monitors reset. on the Mercedes-Benz GLC equipped with 2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC.
Other Common Fault Codes on Mercedes-Benz GLC
Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Mercedes-Benz GLC:
4. Mercedes-Benz GLC P0300 FAQs
What causes code P0300 to trigger on a Mercedes-Benz GLC?
On the Mercedes-Benz GLC (2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC), P0300 is most frequently caused by Worn or fouled spark plugs and damaged spark plug wires or Failing ignition coils or coil packs.
Where is the OBD-II port located on my Mercedes-Benz GLC?
On the Mercedes-Benz GLC, the 16-pin DLC diagnostic connector is located Driver lower kick panel near hood release lever. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.
Can I safely drive my Mercedes-Benz GLC with code P0300?
No. Driving with a flashing check engine light causes irreversible catalytic converter damage. Given that P0300 carries a Critical severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.