Transfer case fault

The flashing lights indicate the transfer case control module was not able to complete the shift as requested. On your 2001 Chevrolet Blazer the light for the desired shift will normally flash until the shift is completed. The transfer case control module will store fault codes. In order to diagnose the problem with your 4wd system these stored fault codes will need to be read and diagnosed.

after pushing 4-hi or 4-low button when at complete stop, put blazer in reverse and accelerate for a second, brake, and then shift into drive as normal and see if the indicator lights up properly . i had to do the opposite when mine wouldn't shift out of 4-hi or 4-low and it worked .