I have 1993 honda accord LX, automatic transmission. When I disconnected NM speed sensor from the power connector to the wiring harness. I looked at the power cord (it has two pins). It looks a little black in there. It does have two leads. And those don't seem to be burned out.
Anyways, when I wanted to perform the continuity test. I first disconnected the battery, then I disconnected the TCU. Then I switched to continuity mode. Which is the sound symbol on the digital meter. Also I touched the two probes together to indicate a beep that it is working.

How I first did it, was I connected the black probe to a ground anywhere on the car. Then I took the red probe, and I tried putting it in one lead. All I got was a OL. Then I tried the other lead and I got a OL. Then I disconnected the shift solenoid's power connector.
And I tried that one I got the same result.

So I did some digging and decided I could put my black probe into the lead and red probe into the other lead. And I got the same result. A OL. I was expecting a beep response indicating that it would be 0 and there would be a beep indicating that the flow of current is working. However it doesn't do that. So I tested the shift solenoid and it doesn't do that as well. Now, in my mind I know that these power connectors that connect to the wiring harness can't be all be broken can they?

There is this article on the internet when you test a power cord doing the same thing. It shouldn't beep that would indicate its bad.

But then there is this other article on the internet if the meter does not beep or it shows 1 or OL it means its open (the path is broken) the component does not allow the flow of current. It means the meter should beep. But that other article indicates it shouldn't beep.

I just want to test if this power connector is bad or good. I want to check for a possible short to ground. Am I doing this right?


Update: I connected the battery. I just did a voltage test on the NC Speed sensor power connector. I got nothing. I also did a voltage test on the shift solenoid speed sensor. I got nothing. Now I'm wondering if some sensors on the car don't receive power until it's turned on? Or maybe it's because the TCU is plugged in?

On my tech guide. It says this "The NM or NC speed sensor (code 9) should be within 400-600 Ohms at 20-degrees C. If they are not within spec replace them. If they are within spec check for a possible short to ground but first unplug the harnesses at the TCU."

The NM speed sensor itself was in range for the OHMS. But what it says next it's not real specific how to check the power connectors for short to ground. But I would assume if ground isn't working on a power connector you wont have any voltage indicator on that power connector. I'm assuming that it wants you to do a continuity test on those sensors with the battery unplugged and the TCU unplugged. But for the voltage test maybe the TCU needs to be plugged in? Isn't the TCU the computer that sends those voltage signals? I could be right on this. Anyone have knowledge on this?


Update: I finally figured it out. I was suppose to turn the key to the start position. Then it sends out signals to all the speed sensors. I tested the grounds, they were good. And I got a small voltage reading. Although I don't know if those voltage readings are accurate. But they are both the same.

 

Did you ever get this figured out? What is the issue that you are addressing with the transmission, just the code 9, or is there something wrong with how the transmission acts?