2001 Impala AC/Fan problems

My 01 Impala temp gauge and ac control all went out at the same time. When this happenes, the ac wont work and the fans stay on. No SES light comes on but if i check my DTC's on the scanner, the P0128 code is in there.(Coolant temp below regulating temp)
If i clear the code, the guage and ac will come bak on (but not always)

I've replaced the entire AC control Module already. What next?

Thx

Try the BCM