Blink code retrieval: No result from DM button/light OR PIN #19

[zentoed]

I just bought a blink code reader and in attempting to do the initial code retrievals, got no results at all from PIN #19, OR the included DM button/test light.
The other pins resulted in mostly one blink/no malfunction, except for PIN #30. But when I tested PIN #19, I got no response after holding the button on the tester down for 2-3 seconds. There is what I believe is a DM test button and LED. I tried getting codes from that with the same (non)result. Any suggestions as to why I am not getting the expected flashes?

I did some reading yesterday and checked the fuses in the module and attempted to ensure that the modules were seated completely. I did get some movement on the modules when seating them. It seemed like they would "rock" a little bit when I hit one side or the other with my rubber mallet. Is this rocking an indication that they are indeed NOT seated? I read that it takes considerable force sometimes to seat them, but I am reluctant to really bash on them.

The car is a '94 500E. It is a recent purchase and was running without any issues. In an effort to improve the car and fix common issues, I inspected the wire harnesses and they were original and in bad shape. I replaced the harnesses and the PCV hoses, had the ETA rebuilt and the car is running fine but I'd like to figure out why I am getting no result from DM.

Thanks in advance, and also for all the info already provided here.

 

[zentoed]

Maybe an admin could move this to the Decoding threads?
My bad.

 

[gsxr]

If the CEL is not on, there may be no codes on the DM. And if so, the DM does not always indicate 1 blink to show "no codes", it may not blink at all. If the CEL turns on in ignition switch position 2 (all cluster lights on), and turns off after starting, I wouldn't worry about it.

 

[zentoed]

Thanks for the quick reply.
The CEL does illuminate during light check and is not on after starting, or any other time. So, I will not worry about it.

While I have you, one other clarification...
When I read PIN 16 ACC, the test LED was dimly lit after hooking up test probes. I was still able to initiate the test. While I pressed the button on the tester the light got brighter. Then it dimmed and gave me one bright blink (indicating no codes?) and returned to dim. I assumed this was a viable test with the addition of a dim light during the "resting stage" of the LED.
Does that sound right?

 

[gsxr]

Your pin 16 sounds odd, but if it returned one blink, I'd call it good. Those are just HVAC faults anyway and I almost never check them. You'll know if the HVAC isn't working right, lol...

 

[zentoed]

Right.
Thanks again.