OBD2 connection failure

Earlier this week, I had to run my Jeep through Az. DOT Emissions to renew Registration. THeir OBD2 reader couldn't make connection. I did the usual research, (Googled it), and found basically two answers,
(1) Hot to check for power, which it has, and
(2) reset the computer by disconnecting the battery, which I did.
Resetting it worked, but their reader still had a hard time making connection. Even on my cheap Hobo Freight reader, I can cake a connection, but it doesn't read my VIN.
Is this "normal"? I just hope nothing else is going wrong, going wrong, going wrong, going wrong. You get the idea.

ItchyDong said:

Good power needs a good ground. Make sure pins 4-5 can light a test light.

Most cheap scan tools only pull mode 1-7. Vin recognition is Mode 9. An aftermarket scan tool that utilizes OEM protocols (not obd2) will pull the vin data with no issue.

Click to expand...

It pulls the VIN on my 2006 Durango.

macleanflood said:

How much corrosion on the pins? Sometimes a can of electronic cleaner and a brass brush will do wonders.

My 12v pin was so corroded it disintegrated. I ordered a whole connector and pigtail on Amazon for $15...depinned the 12v and just replaced that one.

Might want to check your PCM connectors and battery terminals too.

-Mac

Click to expand...

Wire brushed the thing before testing. Nice and clean.