Code 43 = Electeroic Spark Timing (EST) circuit low voltage detected
OR
ESC circuit problems.
Without being there to put a meter on different components and check it out, all I can do is point you to the electronic spark control module.
More information is needed.
I have a brake fluid leak on a Chevy truck silveraldo
Buy a new truck.
By removing it and replacing it with a bran new one.
Replace it.
Probably needs lubrication and the control cable adjusted
You will have to replace it. The bearings are worn out in the blower motor.
replace cat
Start with replacing the thermostat.
change your o2 sensor
I've got a better question, why is this question in the Chevy venture forum ?
Replace the high speed relay.