I recently purchased a 2011 Grand Sport with the NPP exhaust option (yeah, I know, I gotta update my avatar).

About 1000 miles in to the 2200-mile trip home, I was passing on the highway and the exhaust opened up like it should, but after moving back over and letting the RPMs come down, the exhaust stayed open.

I removed the Mild-2-Wild completely to see if that was the issue, but no dice. I checked the vacuum line at the rear of the motor; not only is it in great shape, but it was still under vacuum (hard to pull apart at the QD fitting, hiss of air entering the hose when I pulled it apart), even after the car had been off for 2 days. I then re-installed the mild-2-wild and tried to hear any sort of click or solenoid actuation near the back of the car while I pushed the buttons (I believe this is where the vacuum solenoid would be?) and heard nothing.

My guess is that the controller or solenoid has gone out. I'm thinking I'll just put something like this in the line and see if I can power it from the M2W switch and call it good. Would there be any issue with this (other than that it'd be manually controlled always, and the car would never open the cutouts on its own)?

Where does Corvette forum say I should go regarding troubleshooting/repair?

 

Are you sure the NPP solenoid is getting power? Maybe the fuse blew... an NPP system with a blown (or removed) fuse will be open all the time, as you describe.

All the M2W does is remove electrical power from the stock NPP system -- it has no additional relays or solenoids, nor does it "activate" the existing solenoids. It is *exactly* the same as if you would just wire a mechanical on/off switch into the NPP's power wire (and allow you to use a remote to flick the switch on/off, of course).

Hopefully with that info you can troubleshoot a little deeper.

 

When I removed the M2W I replaced it with a good fuse.

 

When i got my new to me 13 GS a couple of months ago the valves would not close. Checked the fuse and it was blown. I put in a couple of new fuses and they each blew as soon as i started the car. Turns out the solenoid was shot and had to be replaced.

 

The problem could be as simple as used up batteries in the remote that lack the power to transmit a signal. Just like Kent1999 said, the M2W merely is a switch that inserts in place of the fuse. The old school toggle switch or push-on/push-off switch wired directly will work as well.

 

The Mild 2 Wild is not the problem.

The exhaust does not operate even with a good fuse in the fuse box and the M2W completely removed from the system.

I do not understand why I have to keep reiterating these points.

 

Maybe you should have done the bold font all in caps. That should solicit some willing responses and helpful replies from the people you are apparently frustrated with and yelling at.

 

ok, so you have vacuum at the mufflers, but it doesn't close the baffles? Yes/no?

 

 

[/B]I do not understand why I have to keep reiterating these points.[/QUOTE]

You're really going to be a grouchy old man when you're my age. That's what I thought you were until I looked at your profile and saw you're only 29.

 

Had very similar problem with NPP & M2W. Changed battery in M2W remote - problem solved. Simple to do and if not effective, serves purpose of ruling out a possible problem.

 

Not sure if anyone asked this yet but have you tried to move them by hand, maybe they are seized open.

 

I have vacuum at the quick disconnect at the rear of the motor, and it holds this vacuum over a long period of time so there is not a vacuum leak. The last time I checked it the car had been off for 2 days and there was still a vacuum in this line when I disconnected the QD.

I have not checked for vacuum at the mufflers. I assume there is not, because then the actuators would move. My current assumption is that the valve controller is failed and is not actuating the solenoid.

Thank you for not mentioning the Mild 2 Wild! Yes, I have moved the actuators by hand, they are not seized. They move quite freely and spring back as soon as you let them go.

 

I wasn't yelling. THIS IS YELLING. Bold face is simply emphasis.

I am very frustrated because so many people see 'mild 2 wild' and say something about it being the problem, or that a fuse could be the problem, when in my original post I covered BOTH of those issues.

The problem can not be with the M2W, neither with the controller, nor the remotes, nor the wiring, it's not the M2W ground. It's not a battery. It's not a fuse. It's most likely not a vacuum leak unless there's a check valve somewhere that would prevent the line from the front of the motor to the vacuum solenoid in the rear of the car from leaking down.

I honestly do appreciate that people come here looking to help, but I also appreciate when people read the troubleshooting steps that have been performed before (for the 2nd, 3rd, etc time) suggesting things that I have already ruled out and said that I have ruled out.

 

I goy my 2013 Vette out today and my exhaust stayed open. I disconnected my M to W switch and put a meter on the fuse and electrical system. It's ok. It has to be the solenoid at the back of the car.
Trios, did you buy the brass valve you asked about ? If so did it work ?
I've got to try to take mine off to check if that is my problem.

 

Replace vacuum switch behind rear bumper of car. Problem should be solved.

 

Ok.

So.

Humble pie does not taste delicious. However, I am a big enough man to understand when I need to gulp down a large portion of it, and right now is that time.

When I was doing my first testing, I replaced the M2W with a good fuse. I did not, however, ever check to see that the fuse remained good.

Just now I was out there testing some wiring at the solenoid valve computer/controller (which, in case anyone is wondering because nobody told me this, is located either inside the battery box or behind the carpet on the RH side of the tub above the wheel well), and I noticed I didn't have 12v going to the controller. So I went to check the fuse and sure enough, it was blown. Replaced with yet another 10a fuse and jumpered around the controller (which should actuate the valve, red/white on one connector to tan/white on the other in case someone is interested) and sure enough, fuse blew again (I heard it pop from the back of the car even).

So my solenoid valve is failed to short. Thank you to Kent1999 and GaVette61 for leading this horse to water; eventually, he drank.

Now, how does one go about replacing this valve?

 

I was just reading from another thread about replacing this solenoid and I'm not sure this is something I can do as I don't have the tools or knowledge to much mechanical work.
Here is what I found from an earlier thread.


"take out both passenger tail lights to getaccess to the part.

looking into a tail light hole, The cover is over the solenoid.The fastener on the left can stay attached. The cover appears to be a thickfiber material (very bendable). On the right of the cover is a black push pin.I could not get the pin to come out but pulled on the cover and it came off thepin.\






when you flip the cover from right to leftyou will see the solenoid. I used a small flat head screwdriver and a littleelbow grease to get the rubber attachments off the black attachments. Veryeasy. just be careful with the screwdriver and don't tear the rubberattachments.




just wanted to finalize my older thread. Ijust got the in solenoid from Gene Culley at GMParthouse and it solved theproblem.

At least for me it was pretty easy to determine that the solenoid was theproblem. I pulled off the line going toward the front of the car and noted avacuum on my finger but there was no vacuum coming out of the exit for the hosethat goes to the actuator in the mufflers. Since it takes vacuum to close theflaps and I was getting vacuum to the solenoid I felt it best to replace thesolenoid.

With some detective work from Gene I did discover that a previously reportedpart number on the forum was not what I needed.

The part number for just the solenoid is # 25794610.
If you want the solenoid plus the vacuum lines order #25794609.

I didn't need the vacuum lines and after installing the new solenoid the NPPworks perfectly."
I could not get the two photos to attach here. Hope this works for you.

 

I'm thinking there is a cut wire somewhere and the power is not getting to the solinoid.

 

You could take the vacuum line and bypass the solenoid to verify it closes the flaps. If that works, then the box part of NPP-in-a-box is all you need. It's switchable from open on startup to closed on startup too. Of course, the GM part is only about $50 shipped from several sources.