Thread: Newbie with electrical issues

Hey all! I've lurked the forum a lot as it's been a good resource for me to figure out how to fix things and diagnose things, so I hope I can contribute a little as well down the road.
I have a 1999 GTP, with about 140k km, being an older car there definitely will be some problems to diagnose, which leads to my first problem...

The OBD2 port doesn't make a connection to the ECU/PCM, BUT it does have power. This was tested with a borrowed wired scan tool as well as my own ebay bluetooth scan tool (which I confirmed worked on 3 different vehicles flawlessly).
Running through possible causes, I've looked at fuses for cigarette lighter they aren't blown, I've also replaced fuses for the cigarette lighter/aux as well. Pulling the fuse for cigarette lighter/aux supplies no power to the OBD2 port as you'd expect.

I'm a bit stumped about how to start looking in to this, and what to do next? Some googling has told me that it *may* have a link to a lack of information on the DIC as well, which is further linked to an aftermarket radio being connected which means the DIC doesn't get fed any information? (my DIC has been off since I bought the car, owner said he had it unplugged but it is plugged in as the buttons light and traction button works, maybe just not the "information" part of the DIC?)
I assume the PCM does work because the car is running and driving, but somewhere it's not making a connection to the OBD2? And I'm not sure how to get that working. I hope it's not too much for a newbie to get involved with, so I appreciate any help as to what to do next . (I've tried to take pictures of everything like the inside fuse box, wiring harness, etc, so if that would help I can definitely share them). Thanks folks!

Thanks! It's a stock air box, and the wires off the obd port seem to be in fine condition. I'll take a look for the PCM, and I'm going to take a peek and see if my "cheap ebay adapter" could be a cause itself. Some forums say the really cheap ones might not actually support the SAE J1850 protocols.

Thanks! I finally got to find the PCM. Unfortunately there's no autozone's in Canada, and calling every combination of parts stores and shops nearby regarding using a scanner resulted in "no" or a confused "we've never been asked that". I'm betting on a shoddy reader that just can't use the older protocols (which is almost guaranteed), so I'll try to borrow a different locally if possible. Otherwise, checked every fuse again and they are all good, and I don't see any fraying along the main wiring.

However when it comes to the DIC not working, would you think it has anything to do with the radio/stereo harnesses being mucked around with? The traction buttons work as well as the traction indicators, but there is no info on the screen even with a flashlight shown on it. The 3 buttons on the left make 3 chimes if i hold it for at least 2 seconds with the door open, which is a fun little anecdote, but otherwise they do nothing.

Good news everyone! It was a matter of cheap junk OBD2 reader. So if you're having troubles with your OBD2 reader not connecting, the cheap 2 dollar eBay readers do NOT support all protocols. Get a highly rated one off Amazon instead with good feedback and support! I bought the Veepeak one and it 100% works.
Now I just need to figure out the DIC... Does anyone with aftermarket radio have a working DIC?

So now for the first time I can read some codes, which I'll make threads about later on....

Thanks Bill, I don't know if I have any clear way of testing the DIC so that might just take more research on my part.

Here's the codes I'm being thrown:
P0341 - Pretty sure this started when I got a new harmonic balancer installed, no case relearn was done. The code doesn't specify that but I have a hunch it leads to this code? (maybe I'm wrong). A shop agreed to help me do a relearn so I'll report back
P0440 - This one seems like it might be tough to figure out