Cheap 'n cheerful diagnostic tools

[jason-allroad]

So I spent a fair bit of Sunday Googling about VAG diagnostic code readers.

I thought I'd post a summary of my findings here.

First, the thingie you plug into your ODB2 port, what's at the other end?

• a dedicated reader (eg MaxScan)
• a Windows laptop (generally connected via USB pretending to be an older serial port)
• a bluetooth device (eg phone or tablet)
• a wifi connected device

Being able to use a bluetooth or wifi connected device would be ideal. However, from a software point of view, I found only 2 alternatives:

1. "The HEX-NET WiFi Interface with VCDS-Mobile builtin will turn most smart devices with WiFi and a web browser into a factorylevel diagnostic tool". But it is USD 399, and they aren't shipping outside the US yet.
2. iobd2.co.uk, £96 for the hardware (inc shipping)

So for now, I'm going the old school approach.

I bought a couple of cables (under $12 each, inc shipping, from Hong Kong); one with FT232bl chip, and the other an ELM 327. The aim is to use these with VCDS-Lite running on my laptop.

I also bought a KW809 (said to be similar to VAG 405) for $47 inc shipping from Hong Kong. I ought to be able to keep this in the car, and use it if the laptop is not handy (or I can't get VCDL-Lite running with one of those cables).

One thing to be aware of is that there seems to be a distinction between CAN and CAN-BUS. Things changed around 2005, so depending on whether your car is older or newer (mine is older), you need to make sure your buy the right thing.

VCDS-Lite apparently only works with the older models. It won't work with CAN-Bus vehicles.

 

[kai_h]

As with most things in life, you get what you pay for.
With scan tools - there really isn't any decent competition to the VCDS from Ross Tech. Uwe, from Ross Tech, has been an active member of various VAG forums for many years and his company's knowledge of the internals of these cars possibly exceeds that of VW and Audi themselves in some areas (well, the dealerships at least).

Some of the other units are quite limited in what they can do - save yourself some money in the long run and just get a genuine VCDS cable. It works first time, every time, it's got excellent aftermarket support, most of the instructions you find for scanning and/or tweaking things assumes a VCDS and with a genuine cable you don't have to worry about running an older cracked version of the software that you can't upgrade lest it break.

No, they don't (yet) have a wireless option available outside of USA, but if you get a cheap laptop or even a cheap Windows tablet, it works very well and the VCDS interface has a very generous length USB cable on it.

 

[jon]

How did it go with the eBay cables? Did you manage to get any of the cheaper cables working?
Was the ELM327 chip you bought a bluetooth one? any luck with it?

 

[jason-allroad]

http://www.ebay.com/itm/181410444840 arrived and on first impressions seems to work fine with VCDS-Lite on my Win 7 x64 laptop (VCDS-Lite did say it is a bit slow, but that didn't seem to matter) . There were drivers provided on a mini CD, but I just downloaded the latest CH341SER.ZIP (v3.3 of Feb 2012) from wch.cn.

The $47 KW809 also arrived, but doesn't work very well (at least on my MY01 C5 Allroad).

First, it was unable to read the Audi codes in the Engine section (whereas the above USB cable did).

Second, reading OBDII/EOBD, the progress bar freezes on ISO9141 with "Link error", so you don't get any OBDII/EOBD output at all.

Maybe there are some cars it would work better on, but its pretty useless for me.

 

[bennjamin]

We are all audi owners here , right ? I mean we pay $900 for an oil change so I personally cant see the issue with $299 or $349 US + shipping for an official advanced bit of kit

PS Ill be grabbing one soon for anyone in Sydney to borrow here or there

 

[Osprey06]

The $47 KW809 also arrived, but doesn't work very well (at least on my MY01 C5 Allroad).

...

Second, reading OBDII/EOBD, the progress bar freezes on ISO9141 with "Link error", so you don't get any OBDII/EOBD output at all.

Maybe there are some cars it would work better on, but its pretty useless for me.

You might be in the same situation as I'm in with my '02 S3. The car is not OBDII compliant, so generic bluetooth OBDII dongles won't work (a friend tried a cheap eBay one and no good). The car outputs a VAG specific protocol (KWP1281).

For 'on-the-go' stuff, I ended up getting a WBH-BT4 dongle (which has since been superseded by the WBH-BT5), which supports VAG specific protocols KWP1281 & KWP2000 (and now KWP2089 with the BT5) and run Torque Pro (Torque lite won't work), which has beta-level support for the KWP protocols. It's not a fantastic setup, but it does work. A couple of issues off the top of my head:

1. The dongle doesn't seem to re-connect automatically on ignition-on, so if you decide to leave the dongle in the OBD port 24/7, it needs to be removed and re-inserted to get it to connect with the ecu.
2. Torque Pro support is only 'in beta' and hasn't shown any signs of development in ~18 months. It's good enough at the moment to view and log sensor outputs, but requires the user create a custom map file to get any useful output. E.g. by default, Torque will show engine rpm measured from Block 1 Section 1 of the ecu as 'Block 1 Section 1' and auto-scale the resulting output as needed, unless the user maps that value as 'Engine RPM' and sets a scale of, say 0-8000 - it's really not difficult, but a bit time-consuming (I've been using Ross-Tech's published measuring blocks to do mine. I'm not sure how much variation there is in m blocks between ecus - ross tech shows some variation for I4's and V6's, but not much really). Torque Pro does not support viewing or clearing fault codes via VAG specific protocols and won't allow you to do any coding.

The dongle works ok for on the go stuff (like viewing sensor outputs in real-time - it's easier to view on my phone stuck to the windscreen than look at the laptop on the passenger seat!!) and I have a VCDS cable to view fault codes and do coding when I have access to a laptop.

 

[blackie36]

PS Ill be grabbing one soon for anyone in Sydney to borrow here or there

Bennjamin - did you end up buying the real deal? Keen to know where you picked it up from and how much you spent. I just picked up an SQ5 this week and am seriously considering investing in a VAG-COM cable to use with VCDS.