Weird OBD2 communication issue

[theRedStorm]

I have a 2005 mustang gt and never had these issues before with my car before. Perhaps, it's the emissions/state machine.
I have sct x4 and a handheld cree scanner. Both work perfectly fine on my obd2 port. The other day, I went to my local shop for an Emissions test, (my handheld scanner says I passed all ready monitors and no codes) but the state machine could not communicate with the car. It didn't say failed monitors but simple said failed to communicate with Obd2/vehicle.

What would be causing my handheld scanners to work fine but not the state machine? Are there specific fuses or wires to check for Damage? I read some where about Pin 4 or Pin 5 being specific for their government tests but I need some clarification on what I should be looking for here. This has never happened before and normally I can scan and pass everything with no problems

 

[Juice]

Sometimes computers just refuse to establish a connection. In PA, if that happens, the inspector has the authority to pass the car and note the com issue for the state. But trust me, that won't fly year after year. And a state referee will be visiting that shop in less than 24hrs.
Doubtful there is anything wrong with your car.

 

[DieHarder]

I have a 2005 mustang gt and never had these issues before with my car before. Perhaps, it's the emissions/state machine.
I have sct x4 and a handheld cree scanner. Both work perfectly fine on my obd2 port. The other day, I went to my local shop for an Emissions test, (my handheld scanner says I passed all ready monitors and no codes) but the state machine could not communicate with the car. It didn't say failed monitors but simple said failed to communicate with Obd2/vehicle.

What would be causing my handheld scanners to work fine but not the state machine? Are there specific fuses or wires to check for Damage? I read some where about Pin 4 or Pin 5 being specific for their government tests but I need some clarification on what I should be looking for here. This has never happened before and normally I can scan and pass everything with no problems

Maybe just that connector on the state machine? Do they have more than one reader? If not there should be other locations you can try.