boost control solenoid??

95 riv S/C
141000 miles
getting a DTC p1640 quad driver 1 failure and am trying to diagnose problem
Checking in the service manual i see the devices controled by the QDM#1 are the Evap purge solenoid, Boost control Solenoid and the TCC solenoid. I was going to take a chance and replace the boost control solenoid but i can't seem to find one. does anyone have any recommendation for locating this part ?
thanks for any advice !!

what is the car doing to make you think it is the boost solenoid?

the dealership should be able to get you one, or a used parts place like ed morad (if he has a 95').
are you sure the actual quad driver itself isn't the problem? (like a bad ground on #1 QDM?)

I have been eliminating trouble codes on this car for about 3 months.
It all started about a year ago when it would occasionally not start
( not turn over starter disabled, and fuel disabled) traced to the security system (passkey) I bypassed the security system, with resistors and a remote start module. I was still getting an occasional no start but with the starter turning the engine no fuel. replaced the PCM, and I was then only getting an 18x ignition signal lost Code, I have since replaced the cam position sensor and now I am only getting the P0640 DTC saying quad driver #1 fault. and I am only getting this intermmitantly and not at startup, I can sit an idle for an hour and not get any codes. But if i drive the car it will stutter and then set a code P01640 and a service engine soon light, clear all codes and she starts right up.

Oh,
I have also checked all the PCM grounds

What kind of maintenance have you done to the car? Does it have new plugs and wires?

The codes you're seeing and the shudder may not be related.

i am assuming they are because it only sets the code right after the small shudder. i have eliminated all the codes except for the p1640.
like i said i am hoping for the best here, and the only things controled by the quad driver #1 isTCC solenoid, evap purge solenoid, and boost control solenoid. The plugs and wires aren't new, but they are only about 4 years old. Guess it wouldn't hurt to change them but I don't think it's related to the trouble code.
as far as maintanence oil & filter every 3000 well maintained. I purchased in 2000 with 48000 miles on it.
I stated above P01640 but I was meaning a P1640.

I wouldn't replace the wires if they are that new. When exactly does this shudder occur? Is it repeatable?

is it only in Drive?

intermmitently during any drive no rhyme or reason just cruising usually at 55 MPH or above. runs and drives GREAT just this one small problem. it's so small of a shudder if you didn't know it was doing it you probably wouldn't notice. I am NOT a mechanic but while "troubleshooting last weekend I was revving the engine and notice that if I floored the accelerator while sitting in park it would rev to about 3500 RPM and stall back till it got to 3000 RPMs and then pick back up to 3500, and do it over and over as long as I held the accelerator down is this normal for a supercharged engine? like for protection of over reving without a load ??? while driving it doesn't do this , you can floor it and it just picks up speed as normal just when sitting in park or neutral.
I contacted the dealership today and they don't have a listing for a boost control solenoid, nor do any parts stores I have contacted. the GM service manuals clearly show it as a serviceable, and replaceable part. and even gives detailed instructions for replacement.
So does anyone know where a replacement can be found?? I'm gonna take the service manual to the dealership and show them the part in the book.

I might add that with the scan tool hooked to it while sitting and revving the engine it was showing boost at 100% but when it got to 3500 RPMs and stalled back to 3000 RPMs the boost simultabiously dropped to 0%, and when it started reving up again it went back to 100%

thats a rev limiter and it is suposed to do that to prevent damage to the engine. stop flooring it in park!
can you show us the part?

jhodges wrote:

I might add that with the scan tool hooked to it while sitting and revving the engine it was showing boost at 100% but when it got to 3500 RPMs and stalled back to 3000 RPMs the boost simultabiously dropped to 0%, and when it started reving up again it went back to 100%

probably b/c the scann tool only shows boost as 0 or 100 and not an actual psi or inHg. what kind of scanner are you using? does it show intake pressure readings in inHg? you can take that reading and subtract it from the barometric pressure (~29/30) and then convert that to psi to find your boost.

I wonder if the shudder while driving has something to do with the TCC solenoid...maybe when it trys to lock up the convertor,it fails an pops a code an goes into a limp mode... Boost control solenoid shouldnt have anything to do with the shudder,it would just pop a code saying the solenoid isnt functioning IMO

quote: "I wonder if the shudder while driving has something to do with the TCC solenoid..."

That's where I was going. Shudder is a symptom of TCC trouble, and it's a fairly common problem. Might check scan to see if your TCC is engaged when you experience the shudder. If you had a tuner, you could shut off TCC engage and see if shudder disappears.

Thanks guys,
I was feeling the same as you are that it is the TCC solenoid, but was hoping that it wasn't. I have an actron 9145CP scan tool, it's not going into limp mode though just that slight shudder. it'll do that but then drive and run just as normal. and then it's just that dern SES light.
Thanks again!

If it makes you feel any better, TCC problems can come and go. For example, if sediment is clogging the solenoid, a trans fluid change or flush (yes, I said flush) could help. At about 75K I noticed the trans shifting funny up in OD, slight shudder, then picked up a TCC related DTC on my scanner. Had a flush and then changed fluid religiously ever since, have never seen the code return.

I had the same error code in Dec. 2005 at 133K mi. Replaced the boost solenoid on Christmas Eve - (Yes my dealership was open!) and it's been good ever since.

Funny thing was, the check engine light would come on only when I was cruising at freeway speeds and I let off the accelerator completely. As far as I understood it, that's when the PCM would call for the boost solenoid to go into bypass mode, thus protecting the engine from getting extra boost when it really really doesn't need it.

I had no shutter problems like you speak of but after I put the new solenoid on I swear I noticed a pretty significant increase in HP. It could have been those same HP I gain every time after I wash and wax - not too sure there!!!

Previous to diagnosing this problem I had even pulled the solenoid off the car to check for operation using a car battery with a series resistance to limit the current through the coil. Worked fine then but it turned out to only be working intermittently - one of the worst type of problems to diagnose! Sorry I'm still abroad or I could get you a part number - as I remember the part was $38. It sounds to me like you are more likely to be having a TCC solenoid problem anyways...

well I am going to drain the tranny and replace the filter, as far as I know that has never been done. I did the seafoam thing this morning put a can to about 10 gallons of fuel, and did a top end clean and put a 1/2 can into crankcase, and maybe its just my imagination but I can see a significant performance increase already. I am soooo glad to get the starting problem fixed, I replaced everything PCM bypassed security system, fuel pump relay, and on and on turned out it was the cam position sensor boy that things easy to get to,....LOL. if you got hands the size of a geisha girl. Running really great now just that P1640 code and SES light.
By the way this forum is really great !!! found lots of really usefull information here, like I stated before I'm not a mechanic but I can hold my own with a little guidance. I am going to see if there is a part number on the Boost solenoid on the car I can't believe the dealership can't find the thing in their parts material when it clearly shows it in the GM Service manuals.
THANKS for the guidance guys!!

I hope you changed the engine oil after that top end clean... not only does it loosen carbon deposits..but it will dilute the oil a bit...you dont want all that garbage in your filter either...

I 'm gonna run it about 150 miles and do an oil and filter change. because I put a 1/2 can in crankcase to cleanout everything else. I don't drive the car much during the week anyway, use a company truck.
I can't believe how much better it runs and accelerates

Just for informational purposes, if anyone else is trying to find a "boost control solenoid" ( that is the name of the part in General Motors service manual) That is not what the dearlership parts people call it. They called it a valve kit, and the part number for a 95 riviera is GM part # 12353309( fits other but unsure which). I couldn't get one from a local GM dealership without them ordering it from pontiac michigan (about a week), so I went to the local NAPA store and they ordered it from another dealership and it will be here tomorrow, it's genuine GM part and less than the dealership I talked to wanted by about $7.00.

well got the new boost control solenoid (waste valve) today, came home from work took 15 minutes to change out the part cranked her up and ran her up the I-75 and back at about 85MPH, and no 1640 code set. So I think I found my problem. gonna put in a new set of plugs tomorrow, that may be where I'm getting that shudder from. but at least i got rid of the SES light. preserverence is the key to success!!!

Changed out plugs this morning, and guess what I found backside center a burnt plug.insulator was going bad and tracking. had a large brown spot on insulator runs great now no shudder and back to like new power! No trouble codes all is well in "rivieraville"
Thanks for all the advice !

man i wish things went that smoothly for me!
while we are at it can someone get a pic of the " boostCS" so i know exactly what i need to replace?

Yeah man I'll get a diagram and send it to you. when you remove the engine cover on a 95 it's right at the front right side of the supercharger. right at the last fuel injector it's got an electrical connector, and 2 vacuum lines going into it. one of the vacuum lines goes to the little canister mounted in the same bracket. the other goes to the rear towards the firewall to the vacuum block if I remember correctly. I'll see if I can get a diagram and get it posted today.