Cannot Communicate with Emissions Testing Machine
 

Hey everyone! Having a hell of a time here with getting my smog test completed. Passed without issue last year, but this year it won't even talk to the emissions testing machine.

2008 RL w/Tech Package 100% stock

Here is what I have done/checked so far:

- Took it to 2 different emissions testing centers; Dekra and a local shop. About to take it to the exact shop I passed at last year, it's just far away.
- Completed 15+ different emissions tests over the course of 3 days, split across each location. They were slow, so the techs were nice enough to let me retest multiple times in a row.
- All tests gave the same "result"; "ODB (or maybe they called it a DAD connector?) connector has lost connection with vehicle or come loose from the socket..."
- Checked what fuses I thought could be related to this; all the ones I check were intact. Saw some info about it being related to the cigarette lighter/ACC fuse, but those are intact.
- No CEL's or SRS or any dash lights at all
- I have no issues with any of my systems. Maybe once every 4-6 months I'll get an alert saying "check VSA"; but that always clears itself within minutes and the dealer could not diagnose any issues when I had them check it.
- It wasn't recently in an accident or anything. Most recent work I did was replacing the fog lights, but that went flawlessly.
- I have the Bluetooth XM adapter unit installed in the trunk, but it's been there for a while and I've passed smog with it installed so I'm disregarding that as a possible cause.
- I have converted the AC controls to the 2009 version, works great never had an issue during/since the install.
- Handheld scanners connect without issue. Used both WiFi and cabled scanners. Neither device found codes or had any issues connecting to the vehicle or reading info.
- Removed the ODB plug from the metal mount under the dash, thinking maybe the mount was preventing a solid connection.
- Checked to ensure each cable in the harness, behind the ODB plug itself, is connected and seated properly into the plug.
- Completed fresh drive cycle, confirmed cycle completed, re-tested at both emissions stations; no change still "disconnects".

I called my local dealer and discussed this with them, they said they can hook it up to their scanner...but said their scanner was no different from the over-the-counter ones. I didn't feel like wasting $150 and a 50 mile trip on that, plus the service advisor was a total asshole to me on the phone...so I have not gone to a dealer yet.

Any help or advice would be greatly appreciated. Thanks!

Forgot to mention I'm in Georgia, if that matters.

This is an interesting issue.
You’re saying they initially can connect but then it disconnects?


How old is the battery? RLs are very picky with voltages. It’s my only guess.

right, grab a multimeter and test the battery for 12 volts, then test OBDII port for 12 volts.
if both have 12 volts, next step would be to physically check the OBDII port molex connector to see if any pins have been accidentally pulled out. if so, repin and test again.