Quote Originally Posted by Phil_Miller_86 View Post
This is the only file I have from the PCM and it contains an error.

LS1_0076 - 2004 Avalanche K2500 8.1 4L85E - Error in speedometer.ctz
LS1B_2004 Avalanche 8.1L 4x4.ctz
This should be the latest OEM base file for you based on the Vin number from the file you provided. Hope this helps!