Secondary Air Injection System CHECK ENGINE LIGHT. Unfortunately it is a fairly common C5 issue!
There are many ways this system can fail and cause a CEL...
Here's one way to go about diagnosing the issue and fixing it.

 

Great video and thanks for the shout out but I’m just a shade tree mechanic myself…the only thing is if a solenoid “clicks” whether AIR, Purge or Vent Valve doesn’t necessarily mean it’s good…great video below on testing these solenoids and the C5 AIR solenoid being a ground side switched one.

 

I have not seen this one - I'll watch it!
. My wife watches Netflix, I watch Paul(SD), South Main & Pine Hollow auto repair & Shrodinger's box. I love following along and learning from these guys and I have seen your great input all over this forum- thanks again for that!
Toys

 

I have this problem with my 2003 C-5, with 3800 miles.
I cleared the code a couple of times, but unfortunately comes back. I've been hesitant to take it to the dealer, as I don't know if they will actually fix it, and do not want to be taken to the cleaners in the process. I wish that I had a indy Corvette specialist in my area to check this out. Would feel more confident going this route. I live on the Delmarva peninsula, in Maryland...

 

The AIR system is common on many GM platforms of this era so it is not specific to the C5…if diagnosing this is beyond your capabilities find an auto electric shop in your area.

 

The AIR pump failed in my '98 and there are no new replacement pumps available so the system was removed and codes tuned out.

 

Moved to C5 Tech.

 

You fixed the issue, but you did not fix the problem. Did the customer not want to pay for the labor to correct the problem? You still have an unknown issue with the hokey previous repair….which will probably be the next failure point……..whatever that combination of elbow, zip-ties, and copper line.



Given the source vacuum was an issue, your customer should have also had issues with the HVAC, specifically air coming from all vents, not being able to switch modes, etc.


Your approach covers 2000-2004, but it is important to at least understand the differences with a 1997-1999.

On a 1997-1999 the shutoff valve that controls air from the pump to the check valves is integrated into the A.I.R. pump. There is a separate relay in the Underhood Electrical Center (#40) that is operated by the PCM to control the shutoff valve.



For the same symptom on a 1997-1999, where the pump runs, but you have no air to the check valves, it’s important to use a test light/load at the pump connector. I have seen numerous times where I have been able to command on relay #40…and read 12v at the connector….yet….it will not energize the shutoff valve solenoid in the pump assembly. Sure enough, connecting a lamp/load does not illuminate. In every case with this situation that I have experienced….relay #40 was bad.



Schematic for 1999 below( same for 1997-1998)…..and 2000 for comparison.

 

So, you're saying that replacing the relay might fix the problem? Oh course clearing the codes after the repair..this is a 2003 Z06 with 3800 original miles..thanks so much!!
I do not have all the diagnostics to properly test this particular issue, so if this would correct it, would be great! Otherwise, I'll have to take it somewhere, and I'm wary of taking it to the dealer who will probably just charge me a ton of money without fixing the issue...

 

Who are you asking?

What specific codes do you have?

 

An independent mechanic is a better option for out of warranty vehicles. Your local corvette club may have recommendations.

 

Sorry I was replying to lucky131969.
I read the reply to my question regarding my check engine light, being the secondary air pump system. I believe you stated something about relay #40 being the problem that fixed the issue. If that's correct, I would like to replace that relay first, clear the codes, and see if it comes back. It looks like a can of worms to properly diagnose if the relay isn't the issue. I don't remember the code number, but it said secondary air pump system. I can run it tomorrow, and get that if it helps. I appreciate all the people who took the time to respond to this thread!!

 

So you make this difficult partner, because I asked you for specific codes. You provide none.
I specifically described the differences with a 1997-1999 A.I.R. pump............and you have a 2003
Relay #40 is not applicable to the A.I.R. system on a 2003, and you will find it missing from the 2000 schematic(also applicable to a 2003) I posted.

If you have a P0410 code, why not follow the troubleshooting in the video?.....it's well done.

 

Good stuff - especially pointing out the earlier year C5 SAIS differences!
I do have one problem with your response however - I am Not sure why you said I did not fix the problem... The vacuum source is still connected to the back of the intake & I confirmed that route is plugged. I provided an alternate source of manifold vacuum to fix the issue and I am certain the manifold does not have a vacuum leak from the back of the manifold.
Regarding the Air Cond. The owner hasn't had the car long enough ( since late last fall & this in Minnesota) so he was not really aware his AC was not functioning as it should. Post repair I confirmed all of the modes of his AC worked properly - although his temp drop seemed a tad low - but not too bad.
Thanks for chiming in and adding valuable info!
Toys

 

Right, and it's a good work-around, but there is still a problem there. Did you confirm it is blocked? Yes. How is it blocked and for how long remains to be seen. If/when it becomes unblocked will just be a vacuum leak to troubleshoot, but at least you know where to look first. I'm more of a "make it right" guy...as opposed to "make it work". I know that will involve more labor/time....but it's worth it to me so I don't have to keep a log book of "work-arounds" ....plus I'm getting older...and it's too much to remember To each their own. Both paths get the car on the road, but eventually all the "make it work" items really start to add up with an older car. Part availability and discontinued parts are definitely limiting factors requiring creating solutions. Some folks have started printing their own discontinued parts....which is kinda cool.

Your videos are cool. I wish had time to capture all the work I've done like that.