What is Maruti Suzuki P0300?
P0300 means the ECM has detected misfires occurring across multiple cylinders with no single cylinder responsible for more than the others. On Maruti K-series engines, this typically points to ignition system wear — spark plugs and coils are the first things to check. On the 1.3 DDiS diesel, P0300 is often related to injector balance faults or EGR issues causing uneven combustion across cylinders.
Symptoms of P0300 on Maruti Suzuki
Engine vibrates noticeably at idle and low speeds. Passengers feel the shaking inside the cabin.
Unburnt fuel passes into the exhaust — mileage drops by 15–25%.
Unburnt fuel overheats the cat converter. Blinking MIL means immediate stop required.
Car stumbles and hesitates when pulling away from stops or overtaking.
Common Causes of P0300 on Maruti Suzuki
Affected models: Maruti Swift, Baleno, Ertiga, Vitara Brezza, Alto, WagonR — Maruti K10B, K12B, K12N and 1.3 DDiS engines.
Most common cause on petrol models. Maruti recommends replacing plugs every 30,000 km but many go 60,000+ km without service.
Coil-on-plug coils on K-series engines weaken with age. One weak coil causes P0300 plus a cylinder-specific code.
Dirty or leaking injector causes cylinder imbalance — common on K10B after 60,000 km.
On 1.3 DDiS diesel — blocked EGR causes uneven combustion leading to multiple cylinder misfires.
Professional P0300 Diagnosis in Hyderabad
We start with a full 60-module scan to retrieve all stored and pending codes alongside P0300. Live misfire counter data per cylinder tells us which cylinders are misfiring most. On petrol Maruti models, we inspect spark plug condition and coil primary resistance. On DDiS diesel, we perform injector balance rate testing. Most P0300 faults on Maruti are resolved with a spark plug replacement (₹800–₹1,500) or ignition coil (₹600–₹1,200 per coil) — we never replace parts blindly without confirming the fault first.