NPP Valve Actuation Solenoid Fried!!
07-12-2015, 12:57 PM
#1
Le Mans Master
Thread Starter
NPP Valve Actuation Solenoid Fried!!
During a long drive the other day, all of a sudden, just cruising along, the NPP exhaust went into "open" mode. At first, I thought it was the M2W actuator, so I removed that and inserted a fuse. No dice. So then I used a Mityvac vacuum pump to test the vacuum lines and they held 15 inches of vacuum, so after some searching on these forums, I found that the solenoid is also sometimes the problem. Pulled that out and the picture below shows what I found. The solenoid appears to have melted internally!
Has anyone else seen this? My worry is whether it was just a crappy solenoid or something somehow overloaded it and caused it to melt down?
Has anyone else seen this? My worry is whether it was just a crappy solenoid or something somehow overloaded it and caused it to melt down?
08-23-2015, 02:24 PM
#2
Racer
did you get this fixed?
I also had the same problem yesterday. all on its own, the exhaust went to wild mode. I got home and replaced with a fuse, but the fuse blew today. Whatever is driving the current, also obviously fried the m2w unit... So, I appear to have the same exact problem - 2012 GS with NPP... Did you replace the solenoid with a successful outcome? Or, is there something else you found? Solenoid is behind the passenger inside rear tail light, correct?
**correction - I examined the M2W unit tonight, and found that it has a fuse that blew. Replaced, tested with an independent 12v power source and found it is ok. So, what ever is driving the excess current blew the fuse on the M2W unit, and fuses directly plugged into the fuse block as factory designed. Hope you can verify the solenoid was the culprit for your problem above!
**correction - I examined the M2W unit tonight, and found that it has a fuse that blew. Replaced, tested with an independent 12v power source and found it is ok. So, what ever is driving the excess current blew the fuse on the M2W unit, and fuses directly plugged into the fuse block as factory designed. Hope you can verify the solenoid was the culprit for your problem above!
Last edited by twinarrow99; 08-23-2015 at 11:16 PM.
08-25-2015, 01:19 AM
#3
Le Mans Master
Thread Starter
I also had the same problem yesterday. all on its own, the exhaust went to wild mode. I got home and replaced with a fuse, but the fuse blew today. Whatever is driving the current, also obviously fried the m2w unit... So, I appear to have the same exact problem - 2012 GS with NPP... Did you replace the solenoid with a successful outcome? Or, is there something else you found? Solenoid is behind the passenger inside rear tail light, correct?
**correction - I examined the M2W unit tonight, and found that it has a fuse that blew. Replaced, tested with an independent 12v power source and found it is ok. So, what ever is driving the excess current blew the fuse on the M2W unit, and fuses directly plugged into the fuse block as factory designed. Hope you can verify the solenoid was the culprit for your problem above!
**correction - I examined the M2W unit tonight, and found that it has a fuse that blew. Replaced, tested with an independent 12v power source and found it is ok. So, what ever is driving the excess current blew the fuse on the M2W unit, and fuses directly plugged into the fuse block as factory designed. Hope you can verify the solenoid was the culprit for your problem above!
It still works sort of like the stock NPP: it closes the flaps at idle and very low throttle/light cruise, but once you start to give it throttle it will crack the exhaust bypass valves open real quick - much quicker than with the stock setup and much lower than 3500RPMs.
Glad it was just a fuse on yours and you got it sorted now.
I'm getting used to the way mine works now. I may pick up a solenoid from a dealer whenever I visit the U.S. again, but for now I'm fine with the way it is. I have bigger issues to sort out anyways - like trying to get a TCM tune that keeps my car off the limiter in the 2-3 shift. But that's another story...
08-28-2015, 03:13 PM
#5
Racer
NPP Valve Actuation Solenoid Fried!!
Well, I realized I had a bit left on warranty. Dealer found the solenoid shorted. Will replace tomorrow. Hope the replacement lasts longer than the original...
08-28-2015, 10:19 PM
#6
Race Director
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Location: Raleigh, NC
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St. Jude Donor '15
I have mine connected directly to a vacuum source as well. I find it works quite well like that. It would be nice to have more control over it but not a huge deal.
08-28-2015, 10:31 PM
#7
Le Mans Master
Thread Starter
Thanks again for providing us folks on these forums with valuable information, you cold blooded, black-gloved, always-tinkering, parts killer dude with the unpronounceable handle!!
08-28-2015, 11:19 PM
#8
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St. Jude Donor '15
Haha. No problem! I read the forum for years before finally going the supercharger route.. so I suppose it's about time I give back a little
05-20-2017, 01:33 PM
#10
Le Mans Master
Thread Starter
You don't cap off anything at the firewall. You just need to remove the small plastic one-way valve, shown in the photo below in the NPP vacuum line that's connected on one side to the bent rubber hose and on the other to the hose connector covered with the corrugated plastic cover. Pay attention to which way round it's located so that you can return it to stock in the future if you wish. I had enough slack, so I simply pulled the valve and the corrugated converted connector hose off and plugged the rubber hose straight on to the 90 degree snap lock elbow that connects to the NPP hard line.
Last edited by CI GS; 05-20-2017 at 01:36 PM.
05-21-2017, 03:11 PM
#11
You don't cap off anything at the firewall. You just need to remove the small plastic one-way valve, shown in the photo below in the NPP vacuum line that's connected on one side to the bent rubber hose and on the other to the hose connector covered with the corrugated plastic cover. Pay attention to which way round it's located so that you can return it to stock in the future if you wish. I had enough slack, so I simply pulled the valve and the corrugated converted connector hose off and plugged the rubber hose straight on to the 90 degree snap lock elbow that connects to the NPP hard line.
I repeated the steps just as explained.... I'm not hearing the valves open sitting in neutral...but when I drive around I "Believe" that im hearing them open...
Does the car need to be under load when this bypass is done to get the 2 valves to open?
05-21-2017, 10:09 PM
#12
Le Mans Master
Thread Starter
The valves won't open in neutral. What does it do when you go WOT when you're driving? When the exhaust valves open, you should hear a very noticeable difference in the exhaust tone.
05-22-2017, 02:37 PM
#13
Vacuum solenoid valve (the one you burnt up) powers up to allow a vacuum through it to close the valves. Hence it spends it time energized to allow the intake manfold vacuum to reach the muffler gates to close them
If you have the mild to wild wired correctly, then it should kill the power to the NPP controller itself, the Npp controller will not send power to the vacuum solenoid vavle, which keep the vaccum solenoid vavle closed (no vacuum can pass through it), and your muffler gates should stay wide open.
If the gates are closing, then the NPP controller is still seeing power, which is energizing the vacuum solenoid valve to allow the manifold vacuum to reach the gates.
Bluntly, all the mild to wild switch does is to either allow power to go through this fuse link, or to not allow power to go through this fuse instead.
As for the how the NPP system works, it works via rmp and throttle demand, and when both of these are reached, it cuts the power to the vacuum solenoid valve to close the loop between the intake manifold vaccum to the muffler gates and they spring back open.
Now since the vacuum solenoid valve spends most of its life energized when the car is running, when it burns up, it burns up in the open position. The quick test to check to see if it burnt in the open position, just pull the fuse posted above, and see if the muffler gates still close when the car is started.
If you have the mild to wild wired correctly, then it should kill the power to the NPP controller itself, the Npp controller will not send power to the vacuum solenoid vavle, which keep the vaccum solenoid vavle closed (no vacuum can pass through it), and your muffler gates should stay wide open.
If the gates are closing, then the NPP controller is still seeing power, which is energizing the vacuum solenoid valve to allow the manifold vacuum to reach the gates.
Bluntly, all the mild to wild switch does is to either allow power to go through this fuse link, or to not allow power to go through this fuse instead.
As for the how the NPP system works, it works via rmp and throttle demand, and when both of these are reached, it cuts the power to the vacuum solenoid valve to close the loop between the intake manifold vaccum to the muffler gates and they spring back open.
Now since the vacuum solenoid valve spends most of its life energized when the car is running, when it burns up, it burns up in the open position. The quick test to check to see if it burnt in the open position, just pull the fuse posted above, and see if the muffler gates still close when the car is started.
05-22-2017, 07:33 PM
#14
Vacuum solenoid valve (the one you burnt up) powers up to allow a vacuum through it to close the valves. Hence it spends it time energized to allow the intake manfold vacuum to reach the muffler gates to close them
If you have the mild to wild wired correctly, then it should kill the power to the NPP controller itself, the Npp controller will not send power to the vacuum solenoid vavle, which keep the vaccum solenoid vavle closed (no vacuum can pass through it), and your muffler gates should stay wide open.
If the gates are closing, then the NPP controller is still seeing power, which is energizing the vacuum solenoid valve to allow the manifold vacuum to reach the gates.
Bluntly, all the mild to wild switch does is to either allow power to go through this fuse link, or to not allow power to go through this fuse instead.
As for the how the NPP system works, it works via rmp and throttle demand, and when both of these are reached, it cuts the power to the vacuum solenoid valve to close the loop between the intake manifold vaccum to the muffler gates and they spring back open.
Now since the vacuum solenoid valve spends most of its life energized when the car is running, when it burns up, it burns up in the open position. The quick test to check to see if it burnt in the open position, just pull the fuse posted above, and see if the muffler gates still close when the car is started.
If you have the mild to wild wired correctly, then it should kill the power to the NPP controller itself, the Npp controller will not send power to the vacuum solenoid vavle, which keep the vaccum solenoid vavle closed (no vacuum can pass through it), and your muffler gates should stay wide open.
If the gates are closing, then the NPP controller is still seeing power, which is energizing the vacuum solenoid valve to allow the manifold vacuum to reach the gates.
Bluntly, all the mild to wild switch does is to either allow power to go through this fuse link, or to not allow power to go through this fuse instead.
As for the how the NPP system works, it works via rmp and throttle demand, and when both of these are reached, it cuts the power to the vacuum solenoid valve to close the loop between the intake manifold vaccum to the muffler gates and they spring back open.
Now since the vacuum solenoid valve spends most of its life energized when the car is running, when it burns up, it burns up in the open position. The quick test to check to see if it burnt in the open position, just pull the fuse posted above, and see if the muffler gates still close when the car is started.
I bypassed the solenoid and the butterflies are working as they should now....because bypassing has shown that there are no vacuum leaks and the system functions properly minus the solenoid...I'm 99% sure that it is a bad unit... Also, my fuses do not blow when inserted into their correct spots...so the circuitry must be uninterrupted...
This has been a very thorough thread on Diagnosing the NPP system for faults and I'm sure it will be useful for others going forward...
Thanks Gang!!
Last edited by 2L8LUZ; 05-22-2017 at 07:36 PM.
05-23-2017, 02:48 PM
#15
05-23-2017, 06:09 PM
#17
So I'm a bit confused...its possible to have a BCM fail?? How do I rule this out??
I have the solenoid bypassed and the black/white valve up by the brake booster bypassed and my NPP works just fine with the butterflies actually opening sooner due to the direct vacuum source without the B/W valve in the mix...
I thought I had this solved...lol
I have the solenoid bypassed and the black/white valve up by the brake booster bypassed and my NPP works just fine with the butterflies actually opening sooner due to the direct vacuum source without the B/W valve in the mix...
I thought I had this solved...lol
Last edited by 2L8LUZ; 05-23-2017 at 06:11 PM.
05-23-2017, 06:16 PM
#18
Le Mans Master
Thread Starter
05-23-2017, 08:22 PM
#20
Instructor
