Its been several years since I've been on this forum. My Spectra5 hasn't given me too many DIY problems that I couldn't fix w/o getting info from you kind knowledgeable people on this forum luckily. Recently, I was driving and the car seemed to have lost all power while accelerating from a stop. In fact, while going up a fairly steep incline, I had to have to gas pedal floored just to keep going. I stopped in the nearest parking lot and with the car running, opened the hood and saw no obvious issues with belts, fluids, etc. And there was no check engine light. I drove a bit further and tried to go a bit faster. I noticed the car wouldn't shift up to normal 4th gear. I believe that maybe 3rd was the highest it would go. I stopped again and turned it off. Once I restarted the ignition, the Check Engine light was now on. I managed to get it to Autozone to pull the code. The attached is what they gave me. Basically, its P0700, P0760, P0700, P0760. The most probable issue is the transmission harness from what the code says. Then next down the line could be the less probable transmission solenoids. I did alot of searching on the web for the Spectra and see alot who have had this same problem. The best one I found (and with the fix link included is shown below). The problem is that this thread is several years old so I didn't know if I should reopen that thread with my issue. After having the code pulled at Autozone, I restarted the car and it was back to normal for driving! The light went off the next day too oddly enough. I have since driven it maybe a few miles back and forth to nearest store etc and it has been fine. But I am afraid to drive it back and forth to work (12.5 miles each way) for fear that it may go into limp mode again. From the link below, it seems most probably that a solder joint may have gone bad with these cheap Chinese made wire harnesses. I'd be up to venture and try and resolder a joint that may have gone bad but with everything apart in the trans at that point, I'd feel more comfortable to just go ahead and replace the entire transmission wire harness. But I had no luck at all finding the proper stock # for this transmission wire harness for my 2008 Spectra5 SX. I may even have to buy the harness and have my local garage install (but they hate to install something that I bought obviously so it would be more $).
Oddly enough I want to mention that the day that this limp mode issue occurred, I poured a few ounces of Sea Foam into the engine oil. I don't know how this could affect the transmission fluid but thought I'd mention it.
At this point, the car is only worth 900 trade in and that is in working condition w/o issues. If they see that it has a trans problem by pulling up the history codes prior to trade in it will be worth nothing and I just put 1500 into it last year w/ new radiator, water pump, belts, etc. So I'm looking for any advice from you experts and my next step.
Thanks in advance for your kindness.
link to pertinent issue that I have I believe: