Engine-Codes - Chevrolet - P0300 Chevrolet

P0300 Chevrolet Code - Engine Misfire Detected

- Code Popularity: 688,204 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
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What are the Possible Causes of the DTC P0300 Chevrolet?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty spark plug (s)
  • Faulty ignition coil (s)
  • Clogged or faulty fuel injector (s)
  • Intake air leak
  • Fuel injectors harness is open or shorted
  • Fuel Injectors circuit poor electrical connection
  • Ignition coils harness is open or shorted
  • Ignition coils circuit poor electrical connection
  • Insufficient cylinders compression
  • Incorrect fuel pressure

Code Tech Notes

The P0300 code means that a cylinder(s) is misfiring or is randomly misfiring. Start by checking for intake leaks; intake gaskets are a common cause of multi-cylinder misfiring. If no leak is found, the next step is to replace the spark plugs. If the problem persists, more tests need to be done to diagnose the problem, see "Possible Causes".

There are Factory Service Bulletins for the following Chevrolet models:

All 2000-2013 Chevrolet Models:
2000-2013Chevrolet Factory Service Bulletin OBDII Code P0300

2014 Chevrolet Silverado 1500
2014-2016 Chevrolet Corvette
2015-2016 Chevrolet Silverado
2015-2016 Chevrolet Suburban
2015-2016 Chevrolet Tahoe
2016 Chevrolet Camaro
Chevrolet Factory Service Bulletin OBDII Code P0300

2005-2006 Chevrolet Impala
2005-2006 Chevrolet Monte Carlo
2005-2006 Chevrolet TrailBlazer Models
2007 Chevrolet Avalanche
2007 Chevrolet Suburban
2007 Chevrolet Tahoe
Chevrolet Factory Service Bulletin OBDII Code P0171

2000-2020 Chevrolet All Models
2000-2020 Chevrolet Factory Service Bulletin OBDII Code P0300
This Factory Service Bulletin explains how this condition may be caused by significant carbon build up on the intake and/or exhaust valves due to fuel contamination or incomplete burning of the fuel.


2002 Chevrolet Blazer P0300 Misfire Diagnostics




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How to Fix the DTC P0300 Chevrolet?

Check the 'Possible Causes' listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Search for P0300 Chevrolet Questions and Answers: Search here →

What is the Cost to Diagnose the Code?

Labor: 1.0

The cost to diagnose the P0300 Chevrolet code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)
  • Lack/loss of power
  • Hard start
  • Engine hesitation

What Does the P0300 Chevrolet Code Mean?

A misfiring cylinder causes slight variations in the rotational speed of the crankshaft. The Engine Control Module (ECM) is able to detect these variations by closely monitoring the crankshaft position sensor signal. The signals of the camshaft position sensors are used to determine which cylinder is misfiring. If the ECM detects a misfire rate sufficient to cause emission levels to exceed mandated standards, the Diagnostic Trouble Code (DTC) will be set. Under certain driving conditions, a misfire rate can be high enough to cause the catalytic converter to overheat, possibly damaging the converter. The Malfunction Indicator Lamp (MIL) flashes when the converter is overheating, damaging conditions are present, and the DTC is set. The DTC will be set when the ECM detects a crankshaft rotation speed variation indicating a misfire rate sufficient to cause emissions levels to exceed a predetermined value or a misfire rate high enough to cause catalyst damage.

P0300 Chevrolet Code - Engine Misfire Detected

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