Hello guys, a few weeks ago I was and still am experiencing an issue with this p0603 code after the first startup in well over a year. I had previously made a post related to this but was more focused on the other miscellaneous lights that came on. I will include any information that might possibly be helpful. So currently I have the cel light on, as well as the airbag light on even though I put the lemon seats back in, I don’t think this is related but you never know. There are 3 different things that I can think of that might cause this. 1 The battery is four years old now, and has spent a lot of time on the battery tender. Two poor ground Connections, I relocated a lot of grounds during the wire tech, and I’m worried that one of them might have an issue. Also, the ground for the battery terminal is very loose so I put a piece of brass On the terminal to make it fit tight. Also related to the grounds I tried Using the Oem Ground For the battery On the Fender wall to attach the ground for the passenger side, headlight harness, I noticed that the code happens when this is done, but haven’t proved that it happens When it is not grounded at that location. Three, worst case Bad ECU.

Something to note, I Cut the wires For the hood sensor, and all the washer fluid electrics and shrink wrap them. I did extend the headlight harness side, marker harness, A few others for the engine bay, but nothing super important like the throttle body or maf

The car is currently on jackstands and not running on the road yet, so I can’t drive it to see if there’s any issues but it does rev past 5K. and I unplugged my negative terminal every time I put it on the tender

here, at the pictures of the grounds.