Sorry, but GM has proven to me, a once customer, that they do not provide reliable electronic parts. They rapidly fall apart, are ill designed, are very expensive to replace, and do not work for long.
Yep. I have a Blazer (ugh) and just had to replace the 4WD controller. Last year it was the wiper controller. Not to mention the issues from Dex-Cool (Wrecks-Cool), the AC compressor going out at 70k miles, the alternator, idler pulley arm, radiator, windshield washer pumps, etc. The only item replaced that I don't begrudge was the water pump. It went almost 90k miles.
No more GM for me, unless it was made in 1972 or earlier.