Guide: Diagnosing codes on your VW

Its becoming more and more common that people know how to drive cars but not maintain them anymore. This is due to many things like change in culture and what grade schools concentrate on today. But its not hard to do and the internet has made this information accessible to everyone, you just need to know where to start. For the cost of taking your car to a shop having them diagnose and repair the issue, you may be able to buy all the diagnostic tools and parts and still save money because you don’t have to pay their labor rates. Then you have the tools for next time an issue crops up.

These days cars have lots of electronics and due to this having a code scanner is an extremely important tool for fixing your car. Even if you don’t have a MIL (Malfunction Indicator Lamp), CEL (Check Engine Light) or Engine light turn on your in the dash cluster, codes still may be available to help diagnose your issue. There are many helpful codes that don’t trigger dash lights that can narrow down your issue. So a good first step for troubleshooting any issue is to first scan for codes.

If you don’t have a code scanner, get one. Popular ones for VAG (Volkswagen Automotive Group) are VCDS (formerly Vag Com) or newcomer ODB11, these are much more than code scanners and can actually change programming in your car if you are interested in doing so. If the price tag of these scare you then any ODB2 scanner will work to view/reset codes. If you don’t want to buy one, most auto part stores like Autozone will have scanners available for use in their parking lot for free.

So you have an code scanner, where do you plug it in? Well, you plug it into the ODB2 port. ODB2 is a universal diagnostic port mandated at least in the US since 1995. Commonly on VW’s this is on the drivers side under the dash, your owners manual will be able to give you more of an exact location. It’s commonly colored purple on VW’s. Once plugged in you will want to turn the car on but not start the engine. Each ODB scanner is different so I wont go into details on how to scan, refer to the manual of your scanner for how to do this.

If no codes came up – The issue you are trying to diagnose is likely a mechanical issue and not related to electronics o any sensors that can detect it. On newer cars this narrows down the issue significantly as so much of the components on cars today have some sort of sensor. It doesn’t make it easier to diagnose just reduces what the potential issues. Things like unbalanced wheels, worn out engine mounts and exhaust past the catalytic converter are things that can cause issues that wont trigger a code.

I have a code! – Awesome, first thing is to look up what the code means. Your scanner may give a description of what the code may mean but the description could be universal between all cars if you are using a generic scanner. Ross Tech the makers of VCDS have a great reference page for codes here. There are 911 total possible codes on this site, each one with a meaning. Lets say you got code P1297 or 17705 or 004759, these are actually all the same code depending on how your code reader works. This is a real code I got on my old MK5 GLI which had the EA113 BPY engine. And the first special note on the page was exactly the issue I had. The Crankcase Breather Valve was faulty. Part itself was $112 which after searching google.com found was a common issue and there were third party options that didn’t fail available for slightly more. I also found through searching it was a simple fix and didn’t need to jack up the car, only open the hood and take off the engine cover to access. I ended up going with the third party option after my second OEM Crankcase Breather Valve broke.

Its not uncommon for multiple codes to come up for a single issue. Likely only one of these codes is the real issue and the others just happen to also be affected by the problem or related in some way. There are also some codes that are safely ignored. On my MK7 I have a couple of these safe to ignore codes.

Here is one of the codes output from my VCDS tool. This code didn’t trigger any dash light.

329480 – Heated Passenger Seat
B1806 F0 [008] – Safety Shut-Off due to Occupant Detection
Intermittent – Confirmed – Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 6
Fault Frequency: 5
Reset counter: 155
Mileage: 137245 km
Date: 2019.06.09
Time: 06:31:42

Doing some research this issue is just the passenger heated seats turning off when no occupant is detected. Essentially a non-issue. We can also tell it happened on 06-09-2019 at 6:31:42am and the car had 137245 km on it at the time. This code had been trigger 5 times. This information can all be very useful to figuring out what might of triggered the issue. Did you fill up gas at this time/date? Did you notice a weird sound around that time/date?

If you think you have fixed the issue or think it was a one time thing. Make sure to clear the codes with your scanner. If you have not solved the issue and think you need extra assistance and want to bring it to a shop, leave the codes as is so the shop can use them to diagnose your car.

These are some great resources for finding more detailed answers about your codes what others are doing to fix them:

google.com – this one is a bit obvious but nothing beats starting here first.

golfmk.com – Especially with the newer models this forum has great information. Although forums n general seem archaic I have found that the more knowledgeable car enthusiasts post their information on forums rather than other mediums on the internet. The search function on forums sometimes dont work well so I recommend using Google to search the forums site. At the google search screentype “site:golfmk.com thingsearchingfor” and it will search just that site for what you put in for the thing you are searching for.

forums.vwvortex.com – Better for the older cars but still has great info on the new ones. Again searching it with google using site: forums.vwvortex.com is the better option than the built in forum search.

Facebook groups and Instagram – These are very hit an miss but if want to see what the current trends are or are into more visual mods these are good resources. You will find some technical information here but you have to sift through a sea of people posting glamour shots of their cars or asking very basic question that could be answered by reading the cars user manual. Most social media groups are closed and very specific to the car or another theme, you will likely have to request to join.