Common check engine light codes are listed for you on this page at the bottom. This is not a complete or exhaustive list of every code that could be set in your computer's memory.
Instead, what I did was I went through the entire OBD II code list and picked out codes that I have seen set in the real auto repair world. I also included a short description of what that check engine light means so you do not have to hunt that down elsewhere. In fact many of the check engine light codes that I deal with on a daily basis are in the P0300-P0400 range.
The PO300 series of codes relate to engine misfires. A 300 is for a random misfire as a 301 would be a misfire detected on cylinder number one. The p0300-p0310 range can often cause the check engine light to flash. This is because these codes are serious and could allow unburnt fuel to pool up in the converter.
A flashing check engine light means pull over and tow the vehicle to prevent damage. The P0400 codes relate to the emissions system and fuel vapor leaks (Gas Cap Codes). These in my opinion are common and can experience intermittent failures (see the auto repair video below).
But a lot of times this depends on the make and model. Repair trends for diagnostic trouble codes are a moving target as new issues develop regularly. I have a page that covers check engine light diagnosis that focuses on repair and diagnosis of common problems. Note that these articles are about things I run into as a Fleet Technician. Your exact problem might not be covered yet. I add new information on a regular basis, so check back.
If your specific car problems are not addressed by any these articles your best bet would be to follow a factory issued diagnostic chart for the particular service engine soon light failure. I diagnose OBD II check engine light codes all the time.
I still find it necessary to refer to a professional
auto repair diagram to efficiently solve the problem. Below the car
code list is a link to an online factory car repair manual. That is not
only what I use, but I find it to be the most effective tool in your
fight against the engine lamp.
Bookmark this auto repair and check engine light codes resource page.
The quickest way to diagnose check engine light codes is with a specific diagram! Learn more about the online car repair manuals I recommend that can have you following the factory chart in minutes.
Find out more about how these check engine light codes actually help you fix cars and why they set in the computers memory. Also specific articles for repairing the most common car problems. This next link takes you to the check engine light diagnosis area.
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The about us page will supply more background information on the car mechanic that built this website. Learn why he thinks many people can fix cars with some good auto repair help.