Can I pull ODB2 codes without a scanner?

October 21, 2009 9:39 AM

Can I get ODB2 (ODBII) diagnostic codes out of my 2005 VW GTI without buying a code scanner?

I understand some cars can display trouble codes on the odometer or by blinking the check engine light... though I think the blinking is only ODB1.

Do I really have to buy a scanner? If so, can you recommend a cheap one?

I'm mechanically inclined, and interested in learning, but can't spend a fortune on this.

posted by maniabug to technology (17 comments total)

Just look for one, they really aren't that expensive. There's one on Amazon for $40...
posted by Brockles at 9:43 AM on October 21

Yes, many auto parts stores (like Auto Zone) will let you use theirs for free.
posted by iknowizbirfmark at 9:44 AM on October 21 [2 favorites]

You can pick up a cheap scanner at your local Harbor Freight for somewhere in the ballpark of $50. They're pretty well worth it, especially if you see yourself doing more car work.

In the short run, if you just wanna get it checked out now on the cheap, AutoZone will loan you one for free (provided you put down a deposit).

Happy fixing, and nice car!
posted by thebigdeadwaltz at 9:45 AM on October 21

I went through this with my 2002 VW a couple of months ago. In my area, AutoZone no longer let me use their scanner because they'd gotten too much flack for it from the VW mechanics. The auto shop at Sears let me use theirs though, and the guy was very nice about it.
posted by booknerd at 9:50 AM on October 21

CostCo occasionally sells a bare-bones scanner for around $35. I keep it in my glove compartment. It reads OBDII and CAN codes (and displays the text for the code) and also clears codes (check engine lights).

BTW, I had heard that AutoZone lets you use theirs for free, but the local one I checked with doesn't.
posted by zippy at 9:59 AM on October 21

"Hey, Auto Zone, I'm about to buy this [expensive engine sensor]. Could you check to see if you have it in stock? You do? Great. What does it cost? Wow, $500, that's a lot! Hey, could I come over and use your OBDII code scanner before I order it? Thanks!"
posted by iknowizbirfmark at 10:05 AM on October 21

Be careful. Those really cheap ones might not work on your GTI. They say they'll work on anything, but some have trouble interfacing with the new CAN bus networks.
If you're going to go that route, make SURE that it's CAN bus compliant.

The ABSOLUTE best bang for your buck, if you want to work on your GTI, is to spend about $350 on the VAG-COM made by Ross-Tech.
I'm a professional VW/Audi technician and I can tell you that the VAG-COM is 90% as good as the factory scanner.
It's great if you already have a laptop. The diagnostic cable plugs right into your USB port and the software is really user friendly. You can get as involved as you want. Ross-Tech also has lots of great information on their website like often-updated Wikis about diagnostic procedures and all of the various things you can do with their software. The software updates are free, too.
If you want to get into fixing your own VW, think about making that investment. It sounds like a lot of money now, but if you're mechanically inclined, you'll make that money back in savings in no time.

Aside from that, just swing by an Autozone and get it scanned for free. If you have any questions about the results of that scan, I'd be happy to give you whatever help or advice I can.
posted by Jon-o at 10:16 AM on October 21 [2 favorites]

I've never had a problem with either Auto Zone or Advance Auto letting me use the scanner. They'll loan you tools if you are doing your own repair. And I've never put down a deposit. At worst, they've hung onto my drivers license to make sure I brought the scanner back from the parking lot.
posted by COD at 10:17 AM on October 21

I don't know of a way to read codes without a scanner but I'm no auto whiz.

I have a VAG-COM cable and software and I love it. I didn't want to spend the money but it has helped me numerous times and paid for itself. I hate getting taken at the mechanic, so now whenever I go in, I know what the specific problem areas are ahead of time if the useless check engine light is on. And sometimes I don't have to go in because I clear the codes and the check engine light never comes back on. And I can clear my own codes and see pending codes that were cleared but will zombie back and stuff like that. Doing some transmission work a while back, I wouldn't have been able to get out of emergency creep gear a number of times if I didn't have the laptop right there to clear things out. Helped me too when I was diagnosing and fixing a common ABS failure. Using VAG-COM and a Bentley manual and some elbow grease and this online place that rebuilds parts, I saved hundreds of dollars. Paired with the Bentley manual for your model, a VAG-COM will make you super informed about what's going on in your car and help you make some of your own repairs. For me it's minor repairs, but I still like it a lot.

With that said, it's a lot more advanced than I need. I don't need to know about fuel mixture ratios and, I don't know, torque charts or whatever, but it allows me to do more than the dinky little handheld scanners you buy at Sears for cheap.

I got one of those too once when I was stuck out of town without my laptop that had VAG-COM on it. One thing I noticed when I got back home to compare notes is that that thing only read a subset of what I could read with my VAG-COM. Additionally, it was much more useful to have a whole screen of options and information and realtime feedback rather than a single line of LCD that only gave me a code number.

So, VAG-COM, overkill, but handheld, not good enough. VAG-COM ftw.

I tried the AutoZone borrow once and they said no. Some evasive answer. So I guess it's just variable.
posted by kookoobirdz at 12:28 PM on October 21

Pep boys lets you borrow one.
posted by damn dirty ape at 1:00 PM on October 21

Yes, some cars (like my '02 Jeep) will display error codes via sequenced flashes of the check engine light after you perform a specific arcane ritual of timed ignition key turn ons/offs and/or pressing the trip meter reset light.

I don't know if Volkswagens do this or not, or what the "code" to get them to do so is. Finding an Volkswagen/GTI enthusiast's forum and asking is probably your best bet.

If you decide you want to spend something on a scanner, you might want to consider a ScangaugeII. It does a lot more than just give you OBDII codes.
posted by de void at 1:10 PM on October 21

Substitute "trip meter reset switch" for "trip meter reset light" above. Apologies.
posted by de void at 1:12 PM on October 21

I don't know if Volkswagens do this or not

Just to be clear, VWs don't. You need a scanner, there's no way around it.
posted by Jon-o at 1:23 PM on October 21

If your local auto zone/pep boys/sears won't let you use their scanner, find a VW or Audi forum with local enthusiasts, and there is usually someone with a VAG-COM, who will let you use it (under their supervision) for a beer or whatever.

I have no idea which VW forums are the best these days, I was on vwvortex for a while, but mostly audiworld.com, who had plenty of local helpful VAG-COM owners.
posted by Joh at 2:51 PM on October 21

Just to clarify, Auto Zones near me (Mass/RI) will bring the scanner out to the parking lot and do it for you, but they don't hand over the scanner to you. And they'll repeat the reading r-e-a-l-l-y s-l-o-w-l-y while you write it down and try to mentally process it, if you are at all like me. :7)
posted by wenestvedt at 10:06 AM on October 22

Nthing the VAG-COM.

If your battery ever dies and your throttle body position sensor mysteriously forgets its position (and this happens a lot) the only thing that will reset it is a VAG-COM. Takes five minutes, but it's the difference between the car running fine and the car being barely drivable.

Figure out what towing and one hour of shop labor costs and you've basically gotten half your investment back.
posted by Thistledown at 7:59 PM on October 22

Lots of great info here, thanks everyone! I did wind up buying the cheap ScanGauge II, but had fixed the bad coolant temp sensor by then anyway. The VAG-COM does seem to be the scanner to have for the VW, but I can't justify the expense right now.
posted by maniabug at 4:03 AM on November 23