What are the symptoms of P0300?

Common symptoms include: Rough idle / shaking; Power loss; White or black smoke; Flashing check-engine light (severe).

What causes a P0300 code?

The most common causes are: Injector fault on multiple cylinders; Low compression; Fuel delivery problem; Glow-plug issues (cold); Air in the fuel.

How do you fix P0300?

Read injector contribution/balance data; Run a compression or relative-compression test; Check fuel supply and glow system. Take this seriously. It can trigger a power derate or lead to damage if you keep driving — get it diagnosed promptly.

OBD-II Code Lookup

P0300Serious

Random/Multiple Cylinder Misfire Detected

Engine system

The computer detected misfires across more than one cylinder. On a diesel, a misfire usually means a cylinder isn't getting the right fuel, air, or compression.

Take this seriously. It can trigger a power derate or lead to damage if you keep driving — get it diagnosed promptly.

Common symptoms

Rough idle / shaking
Power loss
White or black smoke
Flashing check-engine light (severe)

Common causes

Injector fault on multiple cylinders
Low compression
Fuel delivery problem
Glow-plug issues (cold)
Air in the fuel

How it's diagnosed & fixed

Read injector contribution/balance data
Run a compression or relative-compression test
Check fuel supply and glow system

Got P0300? Get it diagnosed.

A real technician can interpret P0300 in the context of your truck and symptoms — and tell you what's actually wrong before you buy parts.

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Related Engine codes

P0301Cylinder 1 Misfire Detected

Reference only. A trouble code names a symptom, not the failed part — always confirm with a live diagnosis before repairs. See our Knowledge Base for deeper guides.