Before I share any of my results, I should set the parameters of my test. I'm using the old original JBE right now, with the K96 relay plugged in and active. I had the key in and the start button pressed for this test, and my battery was reading 12.6V for this test.

When I stuck the red probe of the multimeter through the back of the X11010 connector at the white/blue wire while it was plugged in, I got a reading of about 8V. When I disconnected the plug and read the voltage off the white/blue wire's socket on the JBE, I got a reading of 10.9V.

That tells me that while the JBE might not be as efficient as it should be, the main problem lies somewhere along the white/blue wire, or possibly at the X11010 connector.

 

Nice work, very promising, and thank you for the test details!

Did you notice whether the fuel pump ran during the test? Or was the fuel pump disconnected in the rear?

 

During my test, the connector at the fuel pump was not connected. I can connect it and try again if you'd like

 

Sure, connect the pump and listen for whether it runs.

If the pump doesn't run, then a priority item before proceeding further is to run a wire from the + battery post to check whether the fuel pump runs when you supply battery voltage directly to the white/blue wire (JBE bypassed).

 

I plugged it in as normal, fuel pump didn't run. However, when I bypassed the JBE with power directly from the battery, the fuel pump ran!

 

Now we know that when the upstream JBE circuit is fixed, the fuel pump should run!

Where in the white/blue wire did you supply battery voltage?

 

I took the connector off the JBE and supplied voltage directly to the bottom female end

 

That is the best location you could have chosen!

 

What do you think I should do next? Should I consider finding a way to get power to that white/blue wire from another switched power source in the JBE compartment? That NAM post you sent earlier today provides a seemingly good way to do that

 

See below.

I recommend that you repeat these^ tests on the new JBE. If with the X11010 connector unplugged, you get either no or low voltage at the JBE white/blue wire pin, then try swapping in the K96 relay from the original JBE.

If you carefully read through that K96 relay bypass thread, you'll see that many people encountered issues with the original poster's procedure. There may be improved K96 bypass procedures out there, but I think fixing the OBDII connection problem should be given an equally high priority.

 

Alright, I'll repeat that procedure exactly, changing only the JBE variable. I'll be gone for about the next 1-2 hours, but once I get back I'll give that a shot

 

I'll scout for some improved K96 bypass procedures.

 

Custom K96 voltage fix: Solder jumper wire between K96 relay socket terminal 87 and pin 9 of the X11010 connector?

Is this feasible, floodhound?

 

I could be mistaken, but I believe that terminal 87 is the ground socket. At least when I was testing voltages, terminal 30 was the one providing voltage. It was only once I put the jumper wire in there that I could read voltage on the terminal 87 side

 

Here's what my notes say based on your testing results:

 

From service manual:

Terminal 87 (B) goes to the fuel pump/pin 9 of X11010 connector...

 

Would it be a problem then that I'm not reading any voltage off of terminal 87 alone? What I mean by that is that I have no K96 relay installed and no jumper wire installed, I'm just putting the red lead into terminal 87 and reading no voltage (key in start on)

 

You are getting the expected result without relay or jumper wire installed. All is good.

K96 fuel pump relay activation:

1. By supplying ground to terminal 30G voltage via the purple/green wire in black connector (X11008), the DME activates the K96 relay.
2. The activated K96 relay in turn supplies fuse F46 voltage to the fuel pump via the white/blue wire in white connector (X11010) [terminal 87].

 

I repeated this test, with the exact same parameters, except this time with the new JBE. With the new JBE, I was reading 0V at both the socket and at the back of the connector. I tried this with the original JBE's K96 relay and got the same result

 

My dad also wants to know (since he did the original soldering work a week and a half ago) if the metal pins/posts that connect the two JBE PCBs together on the sides actually control anything, or if they're just there purely for structural reasons.

 

I believe they also have an electrical function. Do you see any traces going to and from the pins?

 

Fits with your previous results. With the new JBE installed and the K96 relay removed, what voltage readings do you currently get between the terminal 30 and DME relay sockets and between the F46 and DME relay sockets?

 

I remember seeing some traces on some of them when I had it out last. He's concerned about the board because when he went to desolder the pins, some of the metal connectors at the top of the upper board came off and wouldn't go back on. He said that all of the metal connectors on the bottom of the upper board remained, and he soldered from the bottom instead of the top to get as good of a connection as possible. But even given that, my old board seems to be passing voltage better than the one I bought

 

I can't rule out the possibility that the missing or unconnected posts are contributing to the short to ground (~2.5V drop) at pin 9 and the OBDII problem seen with the original JBE. But as you say, it's puzzling that the new JBE has the same or worse problems.

 

For both tests, terminal 30 to DME and F46 to DME, I get a reading of 12.6V