2019 Silverado WT 4.3L. It's lifted 6" with 35". Hypertech speedo recal. Less than 8k on the truck.
I was driving home Tuesday on the expressway. I lost all gauges (except battery) Every service light came on (engine, stabilitrack, power steering, traction control, etc...) Power to engine was reduced. Power steering assist was pretty much gone. I could not maintain speed. I made it to the next exit, and when I accelerated, it was much better. The next day, remote start would not work. I got gas (when the dash goes dead, I can't see how much fuel I have) after waiting for a pump, I pulled in and barely made it to the hose. I took it to the dealership right then (it made it, thankfully.) The dealership has had it since Tues. I got a call back today that they did a brake controller reprogram and the problem still persisted. They unplugged my OBD port light hookup (Amp style so lights come on with unlock/door open etc...) The dealership is blaming that as the cause. It has been installed since the summer with zero issues (I did try to tie a ground to it once, but the lights never shut off, so that ground had to be on it's own. It's been fine since then.) The technician drove it for ten min and gave it the all clear. I go pick it up tomorrow. The service advisor said that the OBD plugs can cause issues like this when things are plugged into them (the insurance trackers are one that she mentioned.) Not sure I buy into that.
The only changes I made to the truck in the days before this happened are new LED DRL headlight assemblies/PIAA bulbs about ten days before. Those have been OK. I also added four lights on the roll bar over the summer. These are tied into the wiring in the third brake light cab spoiler (The upfitter wires) and the harness end under the dash is wired to the extra slot on the pass fuse box that everyone seems to be using. The ground is to the metal by the driver side fusebox. This has been ok for months. The weekend before the issue, I added LED's behind the grill. I tapped into the same upfitter wire underneath the dash and ran it through the rubber firewall finger for power. I grounded the LEDs under the hood to the RH front fender bolt (Good contact, cleaned of paint.) That was fine for a few days.
All that being said:
Is the OBD port excuse legit?
Is it possible/likely that the ground in the engine compartment is causing all this (since that was the most recent change.) I could run it to the ground that the roll bar lights are using, if needed (wouldn't be the easiest though.)
Any other things I should look into as a cause?
Thanks for any help.