Codes can't be read in 2002 Alero

I have a 2002 Alero 2.2 4 cyl and the gauges, head lamps in auto position, windows, fan, and radio will not come on. When car is off and key turned to acc. radio will work. It still drives ok, doesnt seem to be draining the batt but the check engine light came on. I took it to autozone and they COULD NOT read the codes and didn't know why.

The speedometer, temp and fuel gauges haven't worked for months now and the rest of the accessories not turning on is a recent issue.

The only thing that comes on regularly is the backlight for the dashboard and now the check engine light. I had the ignition switch replaced right before the speedometer, fuel and temp gauges stopped working. I noticed tapping the key sometimes gets the radio, windows, and fan working but not the dashboard gauges. Don't want to replace the ignition switch again since it doesn't seem to do anything for the dashboard gauges. Any ideas?

Was the ignition switch replaced or the lock cylinder/PassLock sensor?

Can data be read from the computer?

The ignition switch was replaced. No data cannot be read from the computer as far as the Autozone and OReilly's people can figure when they tried to read it.

If there is indeed a "no communication" issuse, and not a scanner issue, you will need to check the power and grounds to module, will also need to check the serial data line. Is the fuse good for the module? What module cannot be communicated with? If its a BCM problem, autozone probably does not have the correct scanner.