2007 q7 won’t start

[Cr401]

Hoping someone can help. Have an Audi Q7 2007 that won’t start. Brought it to an Audi/vw specialist and was told to replace two control modules. Replaced those and the car started for about two minutes and died again. I really want to get this thing fixed and am hoping someone might have recommendations as to what to do next.
Codes read 01176
00532
00446

[getslideways]

All of your codes are connected to low power. If you clear them do all three come back?

00532 Supply Voltage B+: Signal too Low
http://wiki.ross-tech.com/wiki/index.php/00532

00446 Function Limitation due to Under-Voltage
http://wiki.ross-tech.com/wiki/index.php/00446

01176 code - key 07-10 signal too low
https://forums.tdiclub.com/showthread.php?t=437265

What modules were changed?

The supply voltage too low is usually common if the battery has gone dead or been replaced. So it may or may not be related. So that is why I asked if the codes have been cleared, or if that code keeps reappearing.

Otherwise it sounds like an immobilizer issue with the key, or a power issue from the battery or alternator.

An easy way to test is if it starts and runs for a short time. Use a volt meter on the battery posts under the hood (the battery is under the seat but there are easy access posts under the hood) and measure the voltage of the battery when running. If its not 13-14 volts, the generator/alternator likely isnt doing its job. If it shows its making the right voltage, and if when the car is off the battery reads 12+ volts, I would try the 2nd key, or replace the key battery and see if that makes a difference. If one of the modules that were replaced have anything to do with the ignition or immobilizer system, they keys may not be setup or programmed properly.

Has anything recently changed to the car prior to this happening?