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, I went through the entire OBD II code
list and picked out codes I've seen set in the real auto repair
world. I also included a short description of what the check engine light means so you don't have to hunt a definition down elsewhere.
In fact many of the check engine light codes I deal with on a
daily basis are in the P0300-P0400 range. if you're wondering what P0171 in the picture on the right stands for, it's Fuel system lean Bank 1. 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, examples are provided in the auto repair video below. Often it depends on the make and model. Repair trends for diagnostic trouble codes are a moving target as new issues develop regularly.
I have an in depth page that supplies problem solving diagnostic tips. If you're looking for pages covering specific issues i have many. The individual articles focus on repair and diagnosis of common check engine light problems. Note that
these articles started out by highlighting 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.
General Check Engine Diagnosis
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.
P1491 Radiator Fan Control Relay Circuit Malfunction
P1494 EVAP System Detection Pump Switch Or Mechanical Fault
P1495 No CCD Messages Received From The BCM
P1740 Trans TCC or Overdrive Solenoid PSI In Gear At 0 MPH
P1756 A/T Governor Pressure Not Equal To Target At 15-20 PSI
P1757 A/T Governor Pressure Above 3 PSI In Gear At 0 MPH
P1762 A/T Governor Pressure Sensor Offset Volts Too High/Low
P1763 A/T Governor Pressure Sensor Signal Too High
P1764 A/T Governor Pressure Sensor Signal Too Low
P1765 A/T Switched Battery Malfunction
P1899 Auto Trans Park Neutral Switch Stuck in Park Position.
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 malfunctions
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 a page about what the code digits stand for.
Do you want to leave here and see what others have to say
about this subject. I'm okay with that. This site was number 1 today for
the search term check engine light codes.
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.