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NeedingAnAudi
10-04-2011, 04:41 PM
Failed my emissions test today, twice. Not really understanding why though, Illinois testing apparently cannot communicate with my ecm. But I managed to with a cheapo $50 code reader AND VW dealership scanners. I talked to the manager and he suggested that my car might not be talking in "generic" mode, and that I might not have power at the obII connector. Our scanners use wireless transceivers, so I am fairly certain there is power at the connector.

I searched for hours on here and google, and while some have had similar-ish problems, no one seems to have had this problem. Anyone know?

Feel like Walky might know whats up.

Corrado_Guy
10-04-2011, 04:48 PM
What tune are you using? Is this a stock management system or have you modded it? It may be able to communicate but it may not be getting the responses it needs from the ECM.

NeedingAnAudi
10-04-2011, 04:58 PM
Should be stock, but with this many previous owners I'm not 100%. I thought that might be the problem, but all other scanners work.

Corrado_Guy
10-04-2011, 06:04 PM
Other scanners work because they are reading codes but when the car is emission tested their computer interrogates yours and expects certain responses. It checks for readiness and probably a whole host of other things and when it doesn't get the correct response the car fails. My car is running Unitronics and shows readiness but it doesn't even have a cat so you know they have made some tweaks. I have to have it tested for emissions pretty soon so I will see how mine works out.

That's not saying that this is the problem though, it could be a problem in the ECM or maybe their end is where the issue is. If it can't communicate to the ECM using the generic OBD-II protocols and you can it shows the connection is working but they can't access what they need. A software flash or a defective ECM could cause this but that is just a guess.

walky_talky20
10-04-2011, 06:33 PM
Feel like Walky might know whats up.

lol. I'm flattered, but I have no idea. I think this is a pretty odd issue. If the other devices are connecting, I don't think the emissions device should have any issues. Things I would try (in rough order, based on a 99.5 AEB):

- Check for power at the Red/Black wire of the Data Link Connector. Should be constant battery voltage at all times, via 10amp fuse #12. I agree if your wireless device is working, it's probably fine, but easy enough to check.
- Disconnect ABS module connector (at abs module) and radio connectors (at rear of radio). Faults in either unit can cause communication issues to the ECU.
- Try a different Emissions Inspection location?
- Try a different ECU?

That's all I got.

NeedingAnAudi
10-04-2011, 07:44 PM
I do have the abs light on for a bad wheel speed sensor, but the module is fine. Also my airbag light is on and I cannot clear the codes. I will also see if I can find another ecu. Maybe one of the techs I work with will know whats going on.

This is just so infuriating. My plates just expired and if I can't pass emissions I will have to park my baby [:(]

NeedingAnAudi
10-05-2011, 12:59 PM
Alright guys. It was the k wire. Wire at the back of the radio. Normally it wouldn't be a problem, but my aftermarket radio would not allow communication.

BzeB5A4
10-05-2011, 02:06 PM
Glad ya got it worked out! I got a spare ECU if you needed.

Side Note: The Emissions aren't very strict here in Illinois (at least the Addison one lol). I passed with k04 turbo, GIAC k04 ECU, test pipe, ABS/Airbag/Brake Lights all on with my old A4. As long as there's no CEL, you should be good to go.

walky_talky20
10-05-2011, 02:20 PM
*called it*, lol. Glad you got it working.

NeedingAnAudi
10-05-2011, 05:19 PM
^^ lol walky, see I knew I had faith for a reason


Glad ya got it worked out! I got a spare ECU if you needed.

Side Note: The Emissions aren't very strict here in Illinois (at least the Addison one lol). I passed with k04 turbo, GIAC k04 ECU, test pipe, ABS/Airbag/Brake Lights all on with my old A4. As long as there's no CEL, you should be good to go.

Addision right off Fullerton on Lombard st. right? Yeah I went there, failed. Failed again, then figured out the radio problem, and was just now rejected lol. Went to the DMV and bought a 5 month extension so I have time to fix my large evap leak. I'm just glad we don't have inspections, my "spark plug anti-fouler" o2 sensor spacer would fail every time lol.

MIDNITEAUDI
10-09-2011, 04:26 PM
They couldn't communicate with my ecu here in Washington and they just put the reader up her tailpipe and put me on the dyno. "Any modifications to the engine sir"? I told them the ecu was recently repaired and no mods. ha! Glad you got it fixed.

NeedingAnAudi
10-09-2011, 09:06 PM
Only half fixed. I have an evap leak I have to track down, but that monitor wasn't on when I got tested the 3rd time, so Illinois doesn't know that. Keep it on the d.l. sssshhhhh lol