Flashing HOLD warning, engine light, and no dash illumination
 

2002 Millenia S - I used one of those handy new lithium battery powered jump start devices to start my car last week. Battery's old, and there's a mystery drain somewhere, so if I don't drive it for a few days, the battery dies. Anyhow, the jump start gizmo worked great, and the car ran fine. Today, I started the car, no problem - didn't need to jump it. A few miles into my drive, the engine light came on, the HOLD light started flashing, and then the dashboard illumination went off. No symptoms from the engine or transmission. Error code showed P1720, indicating "Vehicle Speed Sensor '2' Signal Error." Seems suspicious, since the dash is unlit, too. I'm wondering if there's some wiring issue somewhere, or if that jump start device did something to my ECM, maybe.

Everything seems to be working, except the clock/temp, defrosters, ac/heat. Fuses that I checked are okay. I had pulled the fuse for the electric seats, because it was throwing a fluctuating reading, and I thought that might be what was draining my battery.

Anyone have any thoughts on this? Like how to narrow down the possible cause?

Had someone do something like that to my daughter's car she bought. Dude blacked out the check engine light and the airbag light. Turns out the car had no airbags. He likely stripped them out and sold them. Oh, and there was the matter of the bad O2 sensor which caused the engine to run lean, which on the Cruze due to the way the exhaust is routed caused the engine to burn up the exhaust valves on the Showbox jiofi.local.html tplinklogin 2nd and 3rd cylinders, which cashed the engine.

Knock sensor pigtail
 

I know this is off topic of this thread but since it would not let me do a new one.
my knock sensor wire on my 99 millenia 2.5 is pulled out of the primary side not the sensor connector but the hot side if you will, I need to find a part number to the pigtail to solder in which I don’t mind. I can’t seem to find a replacement connector anywhere.