Solenoid

[Barry Nave]

In short. No boost,no codes. Pump pulls 20" Actuator works by using a brake bleader kit and holds Vac. Pull 12" to actuator, wastegate holds,can't move it.
Any ideals?
Worked fine to day. Truck had one of those days of warm up,Cold down days like 4-5 times.
Went to pick up son friend and power was down and seen on boost gage that I had none.
Is ther a way of testing a solenoid?
Once read of testing for voltage.
Is this just key on or Eng running?

[GMC Hauler]

The soleniod can sometimes get stuck inside. I've heard use a little WD40 and that can fix it up. I didn't figure out this problem until after i had replaced my boost control with a mechanical controller. My problem was also intermittent.

The computer wont set a code for low boost.

Hope this helps.

[Barry Nave]

I can hear a ball like sound inside when I shake it around. I,ve done the WD before once and worked though it,s hard to get it into that pin size hole. Thought about soaking it in a can of WD over night and see if that will do anything.
Ideals?

[Shuck]

I'm actually having the exact same problem right now. Vac into the wastegate solenoid, but none coming out. I tried another solenoid with the same results.

Is there a fuse for these things? What voltage should I be reading on the connector?

Ryan

[Shuck]

Ok, late evening update. I checked the voltage at the wastegate solenoid connector and I have 14 volts with the truck running. When I jumper the solenoid to the battery, I have vac at the wastegate actuator. My only conclusion at this point can be that my connector is hosed. I tried bending the pins inside the solenoid a little to make better contact, but no luck.

Where do I obtain a replacement harness? Is this a common problem? I read every thread pertaining to "wastegate solenoid vacuum" and saw a couple mentions of the connector being the problem, but no solutions posted.

Thanks,
Ryan

[Barry Nave]

Shuck
Same here. Done all that you have other then I did not think about jumping of a cliff tongue.gif I meant the Solenoid.
Search also came up empty. Hard to beleve a wire harness other than some pcm fault.
Solenoid has two pins but does this mean one for power and other for ground or single supply :confused:
Never did have a wiring book,thought why buy one when we have the DP.
I'm sure ideals will start flowing in so for now I'm just going to jump the two holes together.
The solenoid R&R will probley be inorder.
Jumping the solenoid to 12 volt may work but if it is not up to the modulated square wave from the PCM then it's gone.
What bugs me is if yours work on hard wiring but not when plug to the harrness when you have power at the lead.
When you hard wired,did you use both pins as one being +,other-

[ 02-19-2005, 03:08 AM: Message edited by: Bnave95 ]

[Brandon]

Bnave95-
If you already have the plugin boost controler bypass the solenoid and run vaccum straight to the turbo. I haven't had mine hooked up since I got the boost controler.

[David Brady]

I had a similar problem years ago and the mechanic traced it to a damaged wire about 2 inches from the solenoid. After spending time looking and trouble shooting, a little crimp on connector and it was good as new. I have since eliminated the solinoids from the critical path.

[6.2L Driver]

where is this solenoid that you guys are talking about. I think I have a boost problem. I have vacume to the wastegate but seems like the turbo might be slow to spool up

[Mainous]

If all else fails buy a Turbomaster from Bill Heath. No more pump to fail, no more solenoid to fail, no more vacuum lines to fail, no more bad harness connection, more boost when desired.

[Barry Nave]

Brandon
Yes I did just that this morning. Other than I would'nt tow that way for it is very eazy to go over 15# boost under load.Though I have the water back up. Taking off hard the boost gauge went to it's limit.
First problem in 8Yrs. I have'nt tracked down and fixed though I also have had no time to get truck back into my 26x42 garage for I have been reworking my 58 F600 dump. Should be out of the garage after I gotten the F600 painted.
Then I'll track it down and once I find what went on I'll post.
First I'll just replace the darn thing for it has never been changed by me.

[GMC Hauler]

6.2,

The solenoid is on the driver's side valve cover, towards the firewall on a bracket. It may or may not have one or two other solenoids next to it. It will have one electrical connection and a set of hard vacoom hoses, one is orange and one is black.

[Shuck]

Thanks for the suggestions so far. I didn't get any time to work on this today, but will get back to it tomorrow afternoon. I have one final check to determine if it's the connector or the wiring or the PCM. I'm going to plug in some jumpers to the connector and then verify the voltage at the end of the jumpers, then hook the jumpers directly up to the solenoid. If I don't have boost, then I'll have to ring out the wires to the PCM, I guess. Not really looking forward to that, though.

Let me also make a comment: every single thread on this board that comes up when you search for "wastegate solenoid" has someone saying, "buy a turbomaster from Heath." Ok, we get it. A spring will fix this problem. I, however, agree with Kennedy that there is a reason that you want the PCM to have some control over boost. Also, I'd rather get to the root of the problem instead of putting on a band-aid. If I have some bad wires, chances are there are others near it.

In the meantime, does anyone know exactly what sort of a signal the PCM sends to the solenoid? Is it a DC discrete voltage that varies in value or is it some sort of a pulsed signal that I can't truly validate with my multimeter?

[Shuck]

I also should note that I need to change my sig. I sold the suburban. The vehicle I am working on now is a 95 K1500 with a VIN S engine. I don't get an SES light and I know the turbo isn't getting any vacuum (I have the hose disconnedted right now) - is that normal on a 95?

[GMC Hauler]

The signal to the wastegate solenoid is a pulsed DC. You can look at the "duty cycle" with a scantool.

[GMC Hauler]

The PCM doesn't set a code for low boost. Although, it is bad to drive like that. The boost has a cooling effect, protecting the 6.5 from high EGT which can lead to other problems. As you describe your setup, you should not see a code for the low boost. If you unplug the solenoid, you will see a code.

[Barry Nave]

gmc
Does not see low boost,While towing once I lost boost under heavey load,backing off boost came back though would not handle a load. Had a small leak in a rubber connecter. That did give me a 78.
Though I bypassed, I did plug it back in.
Shuck
Hope you fine out before I do so I'll learn of of you :D Both seam to be dealing with the same issue. Are you running with no boost at all then?
I'd be running way over fueled.

[Mainous]

Shuck,

My sincere apologies for suggesting a band-aid. Good luck with your issues.

[BobND]

Tug HARD on each of the wires to the boost control solenoid. I have had two instances where the conductors were broken inside the insulation, and the insulation will just stretch when you pull on the wire, until it tears.

[Shuck]

Mainous. No hard feelings. I understand that is what has worked for you.

The reason I mentioned it is that EVERY thread about this had a post almost exactly like the one you posted.

[Shuck]

Ok, I hooked up my volt meter while the solenoid was hooked up and there is a different story. When the solenoid is in the loop, there is 0v over the connector. Does this mean my PCM is bad? I noticed there is pretty much no reistance in the solenoid, is that normal?

Ryan

[Shuck]

Also rang the wire to the PCM. 0.002 ohms of resistance to the PCM from the solenoid harness, so I think the wire is ok =). I did check to make sure it wasn't shorted to ground, too and it wasn't (of course, then my problem would be too much boost).

So it's looking like time for a new PCM. How hard is it to get the PCM out of the dash? Can I put in a VIN F PCM?

Ryan

[GMC Hauler]

Pull the "ENG 1" fuse in the underhood fuse/relay center. Figure out which side of the socket is the load side. After you have that figured out, measure the resistance from that place in the socket to the the wastegate solenoid connector (the pink wire). My concern is that you can see 14 volts at the solenoid even if there is a high resistance connection somewhere in that circuit. The multimeter has a high internal resistance and draws very little current.

Do you have the light duty or heavy duty engine? If you have the light duty with the EGR solenoids, you could use these in your testing. I dont know if the solenoids are the same (I have the F engine), but if they are the same, you could swap them out and test that way. You could also look at the voltage coming into the one of the other solenoids while the engine is running (assuming you have the wastegate solenoid connected)(again, pink wire) to get some live data. These three solenoids all have a common power supply, via the "ENG 1" fuse. If you can do both, do both tests. The first ensures no high resistance connection from the fuse to the solenoid, and the second performs a load test and tests from the fuse all the way to the power supply, assuming pne of the other solenoids is operating. You could also use a 50 ohm, 10 watt resistor.

I just took a second look at the schematics, and that fuse also powers "ignition volatge positive" directly to the PCM. So it probably wouldnt be the fuse or wiring ahead of it, but don't assume anything.

Don't discount the fuse being bad(somewhat high resistance, dirty connections), its a possibility.

You can do a search for swapping the PCM's from the light duty version to the F version. I know it can be done, but not sure which years are applicable.

The computer can be gotten out in about 10 minutes, through the glovebox. Not too difficult, just tight.

My solenoid measures 42.9ohms hot.

Hope this helps.

[ 02-20-2005, 12:50 PM: Message edited by: GMC Hauler ]

[Shuck]

GMCHauler, thanks for the info. I have the light duty / L56 / VIN S engine. My EGR solenoids are working as I have vacuum to the egr and the vac sensor.

I will, however, verify the resistance on the power wire to make sure it's not a bad connection on that side.

As far as swapping PCMs, I think the fact that it's a 95 makes it a lot easier. It's not OBDII, and I don't think it would care if I had an EGR or not. I'd probably just disable the EGR system anyway as its just putting dirty air back through my engine.

Someone made the comment earlier about running with no boost potentially causing high EGTs. Did the non-turbo 6.5s have a problem with that? I imagine they probably have lighter fueling under load, but wouldn't think on the light duty engine that it would be enough to cause dangerously high EGTs. Honestly, my truck doesn't smoke that much without the turbo. I mean, I can see it in the rear view a little under load, but I think between it being a 95 and a VIN S engine that the fueling is pretty light.

Guess that means I have lots of room for more go-power once I get this fixed! =)

[rjwest]

I had a PCM problem on a gasser.
Quad driver ( Transister ) for TCC went bad,
Could not find problem, Took out PCM , inspectyed for Burnt components, looked ok.

PUT it back in truck, problem fixed.

Somehow I think removing voltage reset the PCM Fault......May want to remove all the connectors
from the box for awhile.

[moondoggie]

Good Day!

There's a brief summary of how this system works at crack in line from wastegate seliniod (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=004746#000003) (Click in colored text.). There

[Shuck]

I already tried a new solenoid. That's what has led me down the PCM/wiring path. I'm going to try unhooking the PCM for a couple hours - I actually may just unhook the batteries. Same result and probably easier to do.

If that doesn't work, then it's off to car-part.com to find a new PCM. This sounds like it would be the perfect time to do an L56 to L65 conversion.

By the way, if anyone needs to buy a new solenoid, I have one for sale. Doubt the dealer will take it back.

[diesel65]

A replacement connector from GM is part# 12102747.
Borg Warner also sells the connector that fits, I don't have that number available, IIRC the part# was PT-187.
That connector has various usage, it will fit the washer pump, the coolant level sensor, the front ABS harness and the wastegate solenoid.
I have had a couple that the wire breaks inside the insulation.

[Barry Nave]

This is good! Still have'nt gotten F600 out of garage. Couple more days and then I'll take all that has been said and try to get to the bottom of my boost trouble. Still have boost bypassed.
With out the turbo I have no power and lots of BLACK smoke :eek:

[Barry Nave]

Shuck
Have you found out any thing?
Got the 58 F600 out of the garage and the 6.5 back in. May have time tonight,more time tomarrow to go through what I've read so far.
If you still got that Silly-nood ;) I could just take it off your hands and try it on mine.
My E Mail bdnave@comcast.net
Your old solenoid had no Res. Yor new one does?
My solenoid had IIRC 49-52 ohms.
This morning I'm printing out this Issue to go over what has been some good info.

[ 02-25-2005, 03:10 PM: Message edited by: Bnave95 ]

[Barry Nave]

Do have volts at connector. Ohms check was none,thought I had ohms at first but not now.
Shuck, If you want to unload the new solenoid E-Mail me.

[DmaxMaverick]

Bnave95

Did you reverse polarity with your ohm meter? The solenoid may have a diode. I've never had one fail, so I don't know for sure. The diagram doesn't show yes or no. I would suspect it does, being it is a PCM monitored circuit.

[moondoggie]

Good Day!

In the two I replaced, they didn't fail electrically, they became plugged & worked erratically. The Wastegate Actuator Solenoid alternately applies vacuum, then air, to the Wastegate Actuator at some low frequency (10 Hz?), the duty cycle being varied. The air is filtered through a little piece of foam that's part of the Solenoid. That's underhood air passing to the Wastegate Actuator through the little piece of foam, then through the Solenoid. Eventually the Solenoid passages get dirty.

I had no success cleaning my 1st one. When the second one got dirty, I figured that for $35 to get me reliable operation, I just bought one & installed it - problem solved. :D

Blessings!

Brian Johnson, #5044

[Shuck]

I haven't had a chance to try unhooking the PCM for a while yet. Have needed the truck to drive lately.

As far as the resistance across my solenoid, I measured it again and it's about 45 ohms, so I must have been measuring it in the opposite direction before.

Bnave95, I sold my solenoid to GMCHauler this week, sorry. I did test with both of them that manually applying voltage opened them up, so I've got it narrowed down to the PCM. I'll probably need to replace it.

Ryan

[Barry Nave]

I took power off,No luck. Not in no big rush for I'm sure after the testing I've done that I just need a replacement.
No problem Shuck,good luck ;)
I should R&R this soon though,just to make sure I'm on the right track.

[Shuck]

Bnave95, I'm at the same place right now. I pulled the power from the PCM for about 2 hours and then went out and tried it again, still no vac on the other side of the solenoid. New PCM it is.

I will probably use this opportunity to convert my L56 over to an L65.

Ryan

[Barry Nave]

L65 :D
Open up that air flow ;)