My LR3 is lit up like a Christmas tree. Suspension, tires, transmission, brake, etc. Plus error messages:
Suspension lowered
Transmission fault (runs great)
Low coolant (it's not)
Check tire pressures (they're fine)
Special programs off
HDC something something something

Spoke to my mechanic, he suggested old battery voltage issue. Changed battery with no change. All of these things couldn't possible break at the same moment could they? ECU?

I can't be the first person this happened to. PLEASE HELP!!!

 

So has it occurred again since getting the new battery?

....it can be caused by low voltage, believe it or not. It doesn't mean all those things are "broken" at the same time, it means there was a sensed low signal and all those systems report up through the same network...in a nutshell. I probably botched some terms.

Other things that can cause those symptoms include but are not limited to:

• Broken tail light (yep)
• Bad Brake Switch
• Corroded wires from water ingress

 

Since you spoke to a mechanic, I assume you also tested alternator output?

 

Check the battery cables as well. Make sure connections are still good at the fuse box and the grounds

 

Wet and/or corroded TCM Module connection to behind the battery

 

Had the same sort of messages recently and the car went into some sort of odd mode where it was drivable but suspension felt weird. I also couldn't get it into Sport mode.

Turns out some numpty has spilt some sort of sticky fluid at some point in the past into the centre console which has caused the electronics to throw a wobbler. Garage cleaned it all up, reassembled and it all works fine now. No parts at all needed. Worth a quick check under there for anything untoward looking if you are getting multiple simultaneous failure messages.