Odds and ends

Got the dealer to check the codes on my car today - 3000 and 3009 - which means I did fix the 3115 by swapping in that battery relay assembly from my spare battery. The tech said my harness is bad. Surprising, since it's not the battery icon lit on the touchscreen; it's the car icon.

Question: I've used my ScanGauge to clear the codes on the car many times over the last couple of days as I messed with it. The triangle goes off, but it comes back on every time. If the car is not running, it might take a minute or two after I turn the key on, but if I clear codes while the car is running, or as soon as i start it, the triangle lights immediately. Yet, when I got the car back from the dealer, the triangle was off and hasn't come back on after the 5 mile trip home. I'm guessing that just as my SG won't read the 3000/3009 codes, it won't clear them either, but Techstream (assume that's what dealers use) does read and does clear those codes. Does that explain it?

However, I have had the triangle shut off before just using my SG and stay off for a little while. I expect that it's going to do that now - come back on after I drive it a bit. So, now I'm thinking that's all that happened after I plugged in that inverter connector - the code turned off temporarily for some reason. Is that strange that it will stay off sometimes for a few miles (maybe 20 at the most), but most of the time it won't?

Anyway, I need a new harness. I have one that I think is good on my spare battery, but I only think that because the triangle went off after I put it on that battery when it was in a car (IIRC). The triangle came back on though, and I've just assumed it was due to one low cell, which is why I set that battery aside. Now, with the way the triangle has cleared for awhile multiple times, and then come back, I'm not sure. Obviously, I need to get Techstream, but until then...

I figured I should check the batteries in my parts car for a good harness. Took the first one out, and in the process of removing the sensor wire side harness, the very last sensor wire broke off at the battery. I haven't inspected the rest of it, figuring that broken wire makes the entire harness worthless. But, I have that wire in another harness I took off a battery - is there any way to swap in that wire for the broken one? I don't see any way for the wire to be removed from the ECU connector. And, this is probably a silly question, but is it possible to splice the battery end of a sensor wire from my old harness onto the broken wire? Like cutting the end off one wire, peeling back the plastic and twisting them together, or finding a tiny butt connector?

Also, I pulled the main relay assembly out of that parts car battery with the idea of using it to replace the one I took out of my spare - want to have my spare battery back in working order too, along with fixing the one in this car. Is there some way to test that assembly, other than swapping it into one of my working cars to seeif it then throws a code? I can't see anything wrong with the one I took out, but the 3115 cleared, so something isn't right.

Similarly, before I toss that parts car battery (all the cells have 0 volts), is there any way to know if the ECU is good? It'd be a big PITA to swap those into a working battery just to make sure they're still good. Is it possible the old cells are still usable - this is a flood car and I'm stupid about electronics, but just wondering if the battery going under water (not sure that it did and no obvious sign) drains the batteries but doesn't ruin them, maybe they just need to be recharged?

Finally, I can't think of why anyone might want that old battery, but thought I'd ask. If it can help anyone, you're welcome to it.

 

Update: swapped in the wiring harness from my spare battery and my CEL is gone, even after driving about 20 miles. Car runs great.