I'm new here this is my first post. My 2006 hhr 2.4 was acting up shifting hard all gauges were jumping around and dash lights going crazy I could still drive it and the car would shift over jus real rough. So I replaced the TCM now the spedo dont work the power steering light on and the car wont shift out of first. So what ive done already is change the speed sensor changed fuse box and fuses put a ground on the TCM tried reseting by undoing the battery overnight still the same problems persist the only codes I have are p0700 and u0100

 

Did you have the TCM re programmed? Those codes say no.

 

No I did not I bought it from advance new. how do I reprogram it.

 

Welcome to the site, A good transmission shop or dealership with a Tech2 scan tool.

 

Why did you waste your money by putting parts in it before knowing the cause of the problem ?
Did some friend "mechanic" tell you to do this to fix the problem ?

 

would they have to be reprogrammed if they’re used?!

 

That was from 2019. Pretty sure New comes blank and needs programming, if you get a used that matches your vehicle you should be able to get away with it.

 

X2^^^^^ a used one is already programmed, get one for your year, and engine size