2003 Chevy Suburban Failed Smog Test No Communication with Smog Machine

I had a smog test done today and my Chevy Suburban failed the OBD II communication portion of the smog inspection. The smog tech tried 3 different hand held devices and said it did not work and needed to schedule an appointment with a specialist.

I came home and connected my hand held digital trouble code scanner and it communicated fine. I think they were trying to rip me off and have more work done. The tech said I could bring it back and it should pass once I told him I was able to talk to it with my device. Why would it fail for OBD communication? Also I inserted a fault and cleared the code to ensure I could talk to the truck and the guy said he could not run the test until I drove it 50 or 60 miles to run it through a drive cycle sequence...I've never heard of that. Any info you could provide would be helpful Thank much.

Answer:

It's tough to say why this particular smog station's smog machine had difficulty conducting the smog inspection. We can only recommend visiting a 2nd smog shop to be certain if an OBD II Data Link Connector fault exists. If you were able to connect at home, more than likely, it should connect and communicate with the smog machine as well.

As far as having to drive your Chevy Suburban for 50-60 miles since clearing the trouble codes; this is correct. While clearing the trouble codes, the scan tool also cleared the Emission Monitors. The emission monitors are internal self tests which the engine control module conducts (while your vehicle is being driven) which ensures all emission systems are a GO. Once the monitors are Ready (complete) the smog test can be performed and assuming emissions are low and no trouble codes exist, pass the smog check.

posted by SmogTips Support