How to Check the Engine Light
How to Check the Engine Light
Have you ever been curious about how to check the engine light when it came on in your vehicle?
In this article, I am going to go over the basics of how to check the engine light using an OBD diagnostic tool. The tool used in the photos will be the Autel MS906BT. It is my personal scanner/diagnostic tool. It is a little pricey for do-it-yourself use, but it is definitely worth it.
Different Scan Tool Options
When the check engine light illuminates, it could be a whole range of different things triggering it. See our previous article about check engine light causes here.
The purpose of scanning the vehicle is to retrieve what is known as a DTC – Diagnostic Trouble Code. The vehicle’s modules save different codes based on different systems.
The 3 major code types are:
P – Powertrain
C- Chassis
B – Body
P codes are things related to the Engine or Transmission. C codes are things related to the Brake and Steering Systems. B codes are things related to the Electrical and Body systems such as radio or airbags. Some code readers will only scan P codes. Make sure you are using the correct tool for what you are trying to do.
Hooking up and scanning DTCs:
OBD Port
Locate the vehicle’s OBD Port. It will usually be on the lower left side of the dash. Some vehicles will hide it in the center console, and if the engineer was really high during design then the Port will be located under the hood in the engine bay, usually near the fuse box.
Connected to OBD Port
Connect your Scan Tool to the OBD Port. If using a wireless connection like pictured above, make sure it connects to the vehicle.
If it does not power up, then the most common cause is going to be the fuse. Most OBD ports gett power from the same fuse as the cigarette lighter, so check there.
Turn Ignition On
Turn the ignition to the ON position. Make sure it is in the right position or the scan tool will have communication issues.
Keep an eye on the Voltage
Monitor the indicator so you can be sure Battery Voltage does not drop below around 10.5 volts.
Select Diagnostics
Select the Diagnostics/Code Scan feature on the Scan Tool then proceed to vehicle selection.
Scanning the VIN
Scan and decode the vehicle information then proceed to read the DTCs.
Scanning Codes on cheap obd tool
Next, you will scan the Engine module for all current and pending DTCs then proceed to the report page.
Fault Codes Displayed
Diagnosing the Codes:
From here you can assess the DTCs that are present and then diagnose the issues as needed. Sometimes you will get multiple codes caused by one symptom, so make sure you look into the description and operation outlines of the system that you are diagnosing.
Check engine light diagnosis can be tricky sometimes, so make sure you always approach it from a simple perspective first. 9 out of 10 times it will be a very simple fix, so at the end of the day remember everything can be fixed with the right knowledge.
This is some really good information on how to check the engine light and also a cool write up on the Autel MS906BT tool.
This is important if that check engine light comes on and you need to save a trip to a dealership or another auto care facility. Remember, your car isn’t able to pass state inspections if the check engine light is on, if this light is on your vehicle needs attention. This is an easy step by step process for using the diagnostic tool and should be bookmarked for future reference. Is the Autel reasonably priced?
Thanks!
That is correct, if the check engine light is on they will pass you during an emissions test, which then leads to more repair and testing costs. So one would definitely want to get it figured out before inspection time.
The MS906BT is a little bit pricey if you do not plan on using it often, I think they are going for around $1,200usd now. There are some more affordable DIY options available, let me know if you are ever looking for one and I would be happy giving a few suggestions
Thank you so much for writing this useful article. I will save a lot of money to follow your instructions to diagnose the engine light problems. I know it will cost a fortune if I go to the car dealership. Your articles give us a very detailed diagnostic guide that we can easily follow.
For me, I do not have any mechanic background and know nothing about the cars, but I can easily understand the procedures to check and find the problem by reading these articles. It is really useful and handy for people who are not familiar with how the engine works on the car.
Thank you so much for this valuable information. I am sure there will be a lot of people who benefit from your website. Thank you!!
Thanks Leo! I am glad you were able to gain some understanding and confidence after reading my guide here 🙂
Let me know if you ever have any mechanical questions and I would be happy to help you before you go to the dealership.
Thank you for teaching me how to check my engine light. When I bought my first car in the late eighties, my dad taught me to service it myself and it was such a great feeling to be able to do this as I saved so much money. As the years went by cars have gotten more complicated and I have since had to take my more modern vehicles to the pros.
However being a women people tend to think I know nothing about cars and they try to rip me off. It would be great to know what the problem really is next time before I take the car in when the engine light comes on.
You are very welcome!
Yeah as technology has progressed, vehicles have advanced a lot. Some new cars have over 50 separate modules/computers in them, as well as about a mile and a half worth of wiring!! So sometimes leaving it to the pros is not a bad idea, that is why we are here 🙂
I get that from a lot of my clientele who are women, I see it often that a lot of shops do not even try to explain things very much to women, as well as using scare tactics to try to sell, it is very frustrating to those of us who are really out here to help out.
Let me know if you ever have any questions before or going to a service center, I can look over diagnosis reports estimates with you.
Hey Gabriel! Even though I’ve started driving since long ago now, I never had proper knowledge on how to fix stuff in my car, and the engine light is part of the list. Needed to make a quick check and came across your article, which was very informative and it helped me a lot. I followed your steps and it worked! Thank you for this very useful information!
-Heku
Hello,
Thanks for sharing your blog on how to check the engine light, it seems like it will be a lifesaver. I have gotten this problem my share of times, and always had to take it to the dealer. This Autel MS906BT appears like it will help me and many others, especially since I am not a mechanic, but this device will save time and money for me after learning how to use it.
Best Regards
Audrey
Thanks Audrey, I am glad this has helped you out and will be of assistance to you in the future! Let me know if you ever have any questions 🙂
Hi! I need to do this and first went to YouTube and found way too many options. Then I started reading some blogs and browsed until I arrived here.
Thank you very much for the step by step guide and the pictures of every part of the process, it is very helpful.
It may be pricey, but I am going to purchase the Autel tool for me and my family’s vehicles. It will be a lot better than going to dealerships every time we get a warning! Thanks a lot for this post!
Your guide is very helpful. Thank you for teaching me how to check my engine light. I will save a lot of money to follow your instructions to diagnose the engine light problems. I know it will cost a fortune if I go to the car dealership. Your articles give us a very detailed diagnostic guide that we can easily follow. However being a women people tend to think I know nothing about cars and they try to rip me off. It would be great to know what the problem really is next time before I take the car in when the engine light comes on.
A debt of gratitude is in order for sharing your blog on the best way to check the motor light, it appears as though it will be a lifeline. I have gotten this issue a lot of times and consistently needed to take it to the vendor. This Autel MS906BT also seems like it will support me and numerous others, particularly since I am not a technician, yet this gadget will set aside time and cash for me subsequent to figuring out how to utilize it.
Best Regards
First things first how much is the Autel MS906BT.Because i think i got to get one and less i forgot i already bookmarked this page for easy access…
In recent weeks before the lock down i have had issues with my car and the engine light was on down so i had to take it for repairs…..For me i want to know whats is the source of such problems when the light comes on thanks a lot for sharing
The Autel MS906BT is my personal scan tool, and a little pricey for a simple tool to keep for home use. I believe they run about $1200 now. Let me know if you are serious about finding one and I can recommend some that a bit more affordable and still great tools.
You are very welcome. Let me know if you ever have any questions, I would be happy to help!
Thanks once again for this very nice tip, I have had a lot of issues with my car and although that time the engine light was one and I had to go to the workshop serval time to get it solve because I had abandoned the car for a very long time…i would get the Autel MS906BT. so as to be able to detect the problem on my own next time