We receive a lot of questions about the check engine light coming on both from local customers and from Subaru owners across the country. The one thing I constantly find myself try to convey is that with out knowing what code is set there is not much that can be done. The light is merely an indication that the Engine Management Computer has set a code and needs to be scanned. Something I realized today when talking to a Subaru owner on the other side of the country about their check engine light is.
“Owning a modern vehicle and not having a code scanner or a great shop to stop by in your neighborhood is kind of like being a parent without a thermometer”
If your are local to us, you may never need one but if you take your Subaru on road trips or don’t have a shop like ours close to you, it’s just as important these days to have a code scanner in your car as it is to have a spare tire.
I have provided a link to one we have found to be easy to use. The cost of the scanner is half of what many will pay to have a Subaru Dealer tell them their gas cap was loose, if you can use a phone you can use a code scanner. Once you have the code, you can at a minimum do a little research and determine if you should continue to drive the car, or get it into a shop.

Justin
All Wheel Drive Auto
“Helping you get more from your Subaru'”
Subaru Owners local to us call 425 828 3600 for help with this or any other Subaru need.
If you live outside of our service area post your question or comment below and we will be happy to help as time allows.
6 Responses
Aside from the overall value of good, routine maintenance, if you don’t resolve the CEL issue and leave the light on, it won’t be able to alert you to more serious issue that may arise.
Hi, I have a 1997 legacy outback. The engine light consistently shows code p740. My local Subaru mechanic says no big deal? I looked it up and it says torque sensor. I have not brought it in while the boss was there just one of the mechanics. Should I press this issue? Btw they rebuilt this Subaru for me.
Hello Nickie,
Not sure why anyone would tell you that a check engine light coming on in relation to a P0740 would be no big deal? It indicates there is an issue with a Solenoid, circuit TCM or ECM.
Unless the advice is the car is still moving so drive it until it dies?
-Justin
Our old Subaru in MA was well known at the local shop. It wasn’t prone to problems, but we did careful, regular maintenance on it.
I would like to mention that there are cheaper OBD2-Bluetooth dongles based on the ELM327 chip on ebay – one could have them for ~$15 shipped from Asia. They work very well with Android Torque app that allows the user monitor basic engine stats and read/reset error codes.
However, it is impossible to capture logs over bluetooth – IIRC, a COM or USB cable is needed.
Third, generic scanners cannot access other brains – e.g. transmission or body control unit. That is the territory of proprietary SSM scanners.
Justin, please correct me if I’m wrong and thank you for your blog!
Hello Stan,
Yes there are lots of options, I was merely trying to point out something with ease of use. There are lots of drivers that would have difficultly using a dongle and a smart phone application, and typically speaking the more tech savvy customers have already purchased one. I do appreciate your contribution
Thanks for posting.
Justin