P0300 on Toyota Vitz (SCP10): Random or multiple cylinder misfire

Short answer: P0300 means “Random or multiple cylinder misfire”. The car’s computer has found a fault in the Engine - ignition system and turns on the Check engine light (MIL). First check: check spark plugs.

Code

P0300

System

Engine - ignition

Dashboard light

Check engine light (MIL)

Also sold as

Toyota Yaris, Toyota Echo (XP10)

Applies to

1SZ-FE (by platform)

Confidence

medium (Toyota Echo 1999–2002 factory diagnostics, same XP10 platform; not confirmed on JDM 1SZ-FE)

Source

carmanualsclub.com

Likely causes

1. Spark plugs
2. Ignition coils or wiring
3. Injectors
4. Low fuel pressure
5. Compression or valve fault
6. Air leak

What to check, in order

1. Check spark plugs
2. Swap coils between cylinders to see if the misfire moves
3. Check injectors and fuel pressure
4. Check compression

Related on this car

• All fault codes for this car
• Warning lights
• Where the parts are (parts map)
• Common problems

Same code on other cars

• P0300 · Toyota Passo (1st gen)
• P0300 · Toyota Corolla (11th gen, E170)
• P0300 · Toyota Corolla (10th gen, E140)
• P0300 · Honda City (5th gen, GM2)
• P0300 · Honda Civic (10th gen, FC)
• P0300 · Suzuki Wagon R (Pakistan, K10B)
• P0300 on all cars compared

← P0171/25 P0301 →

Clearing the code does not fix the fault. If it comes back, the problem is still there. For brakes, airbags and steering, see a trained mechanic.