I’m a little confused how this can be: The GEC (ground wire) is not connected to the main disconnect at the meter. There is no other visible means of grounding at the sub panel located in the basement, or anywhere else in the house. Yet every outlet is reading grounded correctly. How can that be? I assume I am missing something here.
The grounds are landed on the neutral bar which is why the receptacles are testing good. It’s wrong, call it out.
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Paint contamination
Double tapped neutrals
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It looks as though there is no system ground and that the sub panel is improperly wired.
The receptacles are testing as though they’re “good” because they’re grounding back through the neutral.
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What a mess. Looks like you have a 3 wire feed to the sub which is not allowed in this case. The feed to the sub has to be 4 wire so that the grounds and neutrals can be separated at the sub. Until they get that 4th wire fed, it is best to leave it like it is. The GEC is also not connected to anything, but that is a separate issue.
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As others have said, that sub panel needs a four wire feed. The reason the tester shows a ground is simply because it looks for the neutral ground connection to light the bulb. You have it improperly in the sub panel. That square D panel is never supplied with a ground bus. The two shown are neutral busses. Ground busses for that panel are always added during installation and in this case would include a large lug for the 4th wire in the feed (which is absent).
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One important thing to remember is that ground rods have nothing to do with receptacle grounding. Separate systems and functions.
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As Jim implied, a ground rod is installed for surge protection, not grounding of the circuits
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Correct. The main bonding jumper is the single system element required to bond the neutral to the EGC’s. The GEC(s) and electrodes are not designed for clearing faults. In this installation the service appears to have a factory bonded neutral so that portion of the system is correct. As mentioned by others the missing EGC run with the feeder to the sub-panel is the issue. As it appears now the metal enclosure for the sub-panel is not directly bonded to anything and could become energized.
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Thanks everyone for the clarification. I did get the neutral was providing the false ground but mixed up that the gec does not provide the ground or clear the faults- separate function.
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Correct. The ground rod cannot be counted on to clear a fault. The path back to the source will likely have high resistance and the breaker might not trip. The EGCs’ and neutrals are bonded at the first point of disconnect in order to provide a safe and low resistance path back to the source, which should result in the breaker tripping.
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Great explanation. This is something that many people including electricians don’t understand. The concept of ground fault clearing is that the fault returns to the utility transformer via the neutral conductor. The connection to the earth via a grounding electrode like two rods stuck in the earth does almost nothing to open OCPD during a ground fault because the earth is not a reliable conductor for fault current.
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C’mon Ryan, fess up!
You stole that from the Mike Holt Forums, didn’t 'cha?!
Just kiddin’… (maybe!!) 
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I guess in the sense that I have done a ton of reading there and here.@rmeier2 has probably been my biggest source of info though. We are lucky to have him here. Also electric interests me probably more than any other inspection topic, so I guess I retain it better than other stuff, lol.
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Yes, I did know that. Chief Moderator Emeritus. Pretty darn fancy title if you ask me! 
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Yeah, raises a question or two, eh?! 
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Personally, I’m grateful for Rob’s contributions and infinite wisdom here and in the MH forum.
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Thanks for the kind words.
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Well put. Great choice of words to describe the differences between GEC, Grounding Electrode Conductor and EGC, Equipment Grounding Conductor.
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