I recently bought a wrecked 2015 Subaru Outback Premium with eyesight and replaced all damaged parts with new OEM Subaru Parts or used stock parts. The vehicle was hit in the front left side and had no airbag deployment. A few of the wires in the wiring harness to the headlight, fog light, and horn were damaged and repaired by twisting 1" overlapping strands and using a good solder, then shrink wrapping. The foglight ballast was smashed and replaced as well as the headlight. All the voltages seem correct and all the grounds seem good. All the lights work as they should. The front a-arm, strut, and axle were also damaged and replaced. And the ABS sensor was replaced just because. There was no actual frame damage only support pieces and suspension.
After reassembly the vehicle is in limp mode with all the dash lights on. The codes i am getting are p0500, powertrain speed sensor, and three historic faults of P2158 powertrain speed sensor B, U0122 network, U0284 network.
Several times upon starting the vehicle has had no issues, no lights, and drove fine, then upon restarting it will be back in limp mode.
What I have tried.
I have reset the ECU, left the battery off for long periods of time with the entire ECU disconnected, then turned the key on without starting and the codes are back instantly. This is leading me to believe it is an electrical issue and not actually related to the drivetrain.
I have checked the voltage on all effected wires and moved the harness around while checking to see of there were any more breaks. I also checked the resistance on all the ground wires and everything seems good.
I am leaning towards replacing the whole harness but I don't want to do that if its not the issue.
I have attached some pics just because, still waiting on the front bumper to get here then paint.