2001 GMC Sierra 1500 5.3L Secondary Air Monitor

[Aussiehomie]

I have had this truck at the GM dealer for nearly two weeks and they were unable to diagnose why the secondary air system monitor will not pass.

There are two Mode 6 codes related to the secondary air system

 

Can anyone tell me what is actually being measured here or some known fixes for this problem.

 

Thank you

[Jsdirt]

That's just basic computer logic from a cheap scan tool. Can't make any sense of it.

 

I think ScannerDanner has some YouTube videos on diagnosing that system. If not, someone does - maybe Eric O. at South Main Auto. I recall watching one years ago and it was very detailed. Of course, I can't remember a thing about it ...

 

Usually it's either the pump motor failing, or wiring issues, especially on a '01. 

[newdude]

4 hours ago, Aussiehomie said:

I have had this truck at the GM dealer for nearly two weeks and they were unable to diagnose why the secondary air system monitor will not pass.

There are two Mode 6 codes related to the secondary air system

 

Can anyone tell me what is actually being measured here or some known fixes for this problem.

 

Thank you

 

 

Whatever chart that is aside, do you have any DTCs present for the SAI system?  Do you or did you have any other codes present for anything else?    

Edited June 9, 2025 by newdude

[davester]

charm.li should have when the test is run, and what driving conditions are needed to activate it.

[Aussiehomie]

There were no DTCs present. The only items present are the two mode 6 codes.

 

The Mode 6 date table is from GM.

 

 

[Jsdirt]

Still doesn't tell us anything. That stuff needs to be translated into something humans can understand by a more expensive / capable scan tool.

[Aussiehomie]

Since GM had the truck for so long don’t you think their diagnosis equipment could translate what these codes mean

[Jsdirt]

They are giving you B/S information that they know full well nobody can decipher. Par for the course.