DTC P0300
A problem with ignition of the fuel mixture was detected

The engine control module (ECM) uses information from the crankshaft sensor to detect engine misfires and information from the intake camshaft sensor and the exhaust camshaft sensor to determine the cylinder’s misfire. By monitoring the changes in crankshaft speed for each cylinder, the ECM can detect separate misfire events. If the ECM detects a misfire condition sufficient to cause emission levels above the applicable legal standards, the DTC P0300 will be set. Under certain driving conditions, the misfire condition may be high enough to cause overheating of the 3-way catalyst and possible damage. The Malfunction Indicator Lamp (MIL) will flash if the catalyst has overheated, conditions that could cause damage, and DTC P0300 set. May apply to such car brands as Toyota, Chevrolet, Ford, Nissan, Honda, GMC, Dodge, etc.

Possible reasons for error P0300

• Failure of the ignition coil.
• cracked or broken ignition wires.
• worn or incorrect spark plugs.
• low engine compression.
• The ignition timing DTC may be caused by excessive vibration from sources other than the motor. Check the following potential sources:
  – A tire or wheel that lacks roundness or balance
  – Brake discs with uneven thickness
  – Specified uneven road conditions
  – Defective accessory drive belt or belt
  – Damaged reluctor shield
• High resistance in the injector circuits may cause the ignition misfire DTC setting to be set without injector DTC setting. Inspect the injector circuit (s) of the cylinder (s) concerned for high resistance in the event of a suspected fault.
• Engine ignition interruptions are indicated by the MIL flashing.