More on the W126's SRS light and crash sensor

So, from previous posts I am resurrecting a bruised 1991 300SE that had the driver seat belt and passenger airbag deploy. It was in a minor "threshold
1" collision. I found a seat belt retractor, passenger airbag, and a new crash sensor from a reputable dismantler and installed them. The SRS light came on, so I read the codes out today. The replacement sensor read 3,4,5,6,9, and code 10 (control unit activated). The dismantler is sending me a replacement.
Just for the heck of it, I thought I would put the original crash sensor (the one from minor collision) back in to see what codes it might be storing. It read out codes 3, 4 and sure'nuf, code 10. But here is the odd thing - the SRS light is not on! It self-checks fine and then the SRS light goes out!
I still plan to install a "clean" crash sensor but is there an explanation as to why a crash sensor storing a code 10 would not light up the SRS bulb?
Scott D (learning a lot about the W126 SRS system!)
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