so heres the story i have a 02 bonneville 3.8 l engine light is on comes up with a code for low voltage at maf i have pulled the wire off and checked have 12 volts ground and your ref 5.0 volts but im reading 0 with the scanner when i look at the readings and does have a code for seconday air injection pump too any help would be great

What are the codes?

The codes are p01032 p0412 p0418 p0443 thanks bill

Some light reading for you:

https://www.gmforum.com/obd-ii-trouble-shooting-153/p0412-285585/

https://www.gmforum.com/obd-ii-trouble-shooting-153/p0418-285581/

https://www.gmforum.com/obd-ii-trouble-shooting-153/p0443-285580/

https://www.gmforum.com/obd-ii-trouble-shooting-153/p0132-284062/

I will take a look at these tomorrow if I get a chance to see if they tell a story well all put together.

these are all control circuit errors, check all the fuses, i looked at the man. they dont share a common fuse. sometimes a low or failing battery will cause issues like this as well as loose or corroded pos or ground connections

thanks i will test the battery and then do some of the other test