How To: Clean The Camshaft Position Actuator Solenoid (CPAS) Picture Heavy

Playsinsnow

Well-Known Member
Personally I would get an ACDelco. If it doesn't look like what you pulled off :undecided:

Call Rockauto and see if you got an appropriate part or some ccc part. I think airtex is a division of Fram.
 

jeffro312

Well-Known Member
Well overall it looks same there is a screen with holes it just has metal spring/coil wired around screen. I'll try it see what happens not an emergency

Ill post results
 

jeffro312

Well-Known Member
Well installed it no issues noticed my idle is a lot smoother odd could just be due to computer being reset with battery off wich means something is making it run bad with no codes. Ohwell. Spark plugs fuel and air filter on its way. Gunna clean throttle body while I'm at it
 

IllogicTC

Well-Known Member
Playsinsnow said:
Personally I would get an ACDelco. If it doesn't look like what you pulled off :undecided:

Call Rockauto and see if you got an appropriate part or some ccc part. I think airtex is a division of Fram.

Looks to me like a rendition of the updated ACDelco CPAS part. My ACDelco came with the springs, too, which is nice since it helps retain the screens.

The idle will become smoother since the computer once again has proper control over the exhaust cam's advance/retard. It's more noticeable once you actually get out and drive it.
 

fishcreek

Active Member
Just a quick one, is it really necessary to undo the battery? Is it because of the PCM? Can we do this by just unplugging the fuses #10 and #28 like when we are cleaning our throttle body? Thanks in advance.
 

Envoy_04

Well-Known Member
fishcreek said:
Just a quick one, is it really necessary to undo the battery? Is it because of the PCM? Can we do this by just unplugging the fuses #10 and #28 like when we are cleaning our throttle body? Thanks in advance.

I did it by unhooking fuses 10 and 28. Also cleaned the throttle body while I was doing it so that the throttle body relearn would work with a clean TB.
 

fishcreek

Active Member
Envoy_04 said:
I did it by unhooking fuses 10 and 28. Also cleaned the throttle body while I was doing it so that the throttle body relearn would work with a clean TB.

Thank you, I guess we can save your reply for future reference. I was waiting for a reply all morning, got impatient and unhooked the battery anyway. Wish me luck with the actuators..
 

IllogicTC

Well-Known Member
Envoy_04 said:
I did it by unhooking fuses 10 and 28. Also cleaned the throttle body while I was doing it so that the throttle body relearn would work with a clean TB.

The system appears to note when the CPAS is working properly. There's been cases where p0014 shows up, but then disappears. When mine was out, I had the MIL turn off once the system decided it was working "okay." Came back on later, but still. I don't think it's necessary to do a PCM reset for the CPAS, since it's a system with immediate feedback (camshaft angle as compared to trying to figure out why the RPMs are so high, and then deciding to adjust the throttle lower and lower until it sits pretty finally.) It's just good practice to disconnect the battery when messing with electronic systems. I myself didn't. :rotfl:
 

fishcreek

Active Member
Replaced the CPAS today. Reason I did is because my TB was idling funny on a -30C start yesterday, shaking the whole truck pretty much with stinky exhaust. The truck managed to run but not until it had low oil pressure warning, reduced engine power and eventually stop engine. It had a CEL last night but disappeared this morning. Ran fine but I pretty much lost faith on driving it around.

Upon checking the CPAS, I can rotate it with my hand, basically point the harness anywhere I want, not good I figured. So change CPAS it went.

Truck ran fine after, but there is still paranoia lingering.

What's troubling me is "what if" it is not the CPAS that is the problem? What was the CEL? Low oil pressure is scary, it will disable you in seconds. Makes me want to change everything that I can now, oil sensor and oil sender perhaps?
 

IllogicTC

Well-Known Member
fishcreek said:
Replaced the CPAS today. Reason I did is because my TB was idling funny on a -30C start yesterday, shaking the whole truck pretty much with stinky exhaust. The truck managed to run but not until it had low oil pressure warning, reduced engine power and eventually stop engine. It had a CEL last night but disappeared this morning. Ran fine but I pretty much lost faith on driving it around.

Upon checking the CPAS, I can rotate it with my hand, basically point the harness anywhere I want, not good I figured. So change CPAS it went.

Truck ran fine after, but there is still paranoia lingering.

What's troubling me is "what if" it is not the CPAS that is the problem? What was the CEL? Low oil pressure is scary, it will disable you in seconds. Makes me want to change everything that I can now, oil sensor and oil sender perhaps?

Just keep an eagle eye on it. If you have the ability to leave a scanner hooked up while driving, do it so you can hopefully catch a code. A fancy scanner (running the multiple hundred to thousand dollar range) can also read historical codes I believe, and the thing which came up and went away may be in there. That's if you want to make that kind of dollar commitment.

My CPAS was the same way - the outer part and the inner part are two separate pieces but are pressed together where they should feel like one unit. Twisting around the outside means it's bad or going bad, that's how mine was when p0014 showed up. Bad idle can cause low oil pressure, just because it needs to stay at an expected minimum with smooth (relatively smooth at least) operation to keep the oil pump going at an acceptable rate. The oil pressure could very well be tied to your truck's coughing fit, and the coughing fit may or may not be from the CPAS.
 

fishcreek

Active Member
IllogicTC said:
and the coughing fit may or may not be from the CPAS.

That's what I thought and a bit of sad reality. On the bright side, the pros are always here to guide us :thumbsup: Thanks All!
 

RocketQueen

Member
Thanks for posting voymom. We'll be attempting this very thing tonight and will let you know how it goes. I see AutoZone has part #917-010 for $61.99. Any pros or cons to the Dorman part? If it's trashed, which I'm assuming it might be, I don't want to have to wait for a new part by ordering it online. Hopefully, it just needs a good cleaning. Wish me luck!
 

IllogicTC

Well-Known Member
RocketQueen said:
Thanks for posting voymom. We'll be attempting this very thing tonight and will let you know how it goes. I see AutoZone has part #917-010 for $61.99. Any pros or cons to the Dorman part? If it's trashed, which I'm assuming it might be, I don't want to have to wait for a new part by ordering it online. Hopefully, it just needs a good cleaning. Wish me luck!

The CPAS is one of those parts you want to stick to Genuine GM or ACDelco for. This engine seems to know when other aftermarket is put on when it comes to critical components, likely because of build quality and tolerances.

If you have a buddy who works at a GM shop, you can probably get one at cost. Or you can order one from a place like gmpartsdirect.com. I can't remember if the part number is different from 02-04 from 05-up, since they changed the VVT actuator beginning in 2005. Mine was ~45 dollars shipped, ACDelco, from gmpartsdirect.
 

RocketQueen

Member
Ok, we got the one from the dealer that looks exactly like the picture in post #40.
$60.00
The old one actually had one of the "screens" missing.
New one is on and everything sounds and runs great. Gas mileage is up too!
Thanks GMT Nation!
 

BrownHP800

Well-Known Member
Thank you for this thread. Today I got the P0014 code. We bought the TB used so I really don't know about previous maintenance. So I did a Mobil 1 oil change and pulled the solenoid and it looked exactly like the OP. Cleaned it off with some carb cleaner and a soft bristle brush and put it all back in. Ran it for 10-15 miles and I noticed a better idle coming to a stop. I hope that fixes that code!

It was a pretty easy fix. If you have access to an air or battery powered ratchet it makes getting the power steering bolts out much easier. Not much room in there to swing a ratchet.

Thanks to the OP for posting. Great job.
 

Steve A

Well-Known Member
I took the CPAS out and as you can see one of the screens was missing. Instead of putting this old one back in, I'm going to the dealer to get a new one just to be safe.
 

Fire06

Well-Known Member
Just a question i have but does the CPAS need to be changed as maintenance or just when the codes start coming?
 

IllogicTC

Well-Known Member
Fire06 said:
Just a question i have but does the CPAS need to be changed as maintenance or just when the codes start coming?

I'd suggest an inspection as regular maintenance, but only replace as required.

An inspection would involve removing the unit, inspecting for excess debris and cleaning as required. Check the connector for any oil, and check the two halves of the unit to ensure the pressing holding the part which goes in the engine and the part which pokes out cannot turn independently of each other.
 

HARDTRAILZ

Moderator
I replaced mine with codes and have no desire to inspect or just do it to do it. Codes will let you know if it needs done. However mine tossed code for couple weeks and after oil change...its been gone for several weeks. I guess I could inspect but sometimes best to let a sleeping dog lie.
 

Fire06

Well-Known Member
That was my thought but like to stay ahead of the maintenance curve when I can. Fix or maintain stuff when it is suits me not on a shitty day when it breaks
 

HARDTRAILZ

Moderator
I drove for couple weeks after codes before replacement but prolly not best
 

IllogicTC

Well-Known Member
Doesn't necessarily need to be every OTI or anything :thumbsup:

Maybe every time your TB gets cleaned. Unless you clean it religiously, in which case I'd say 25-30k would be a fair measure. It doesn't need done horribly often, in fact it doesn't really need done at all, but if one is willing to do such a thing it's definitely workable to inspect it thanks to its ease of removal.

I'd also go with changing only when codes show up. Codes will show up if the pressing fails usually, or at least it did for mine. It may affect the O2 readings or let a little extra crap down to the cat, but that's just pure darts-at-the-wall-style guesses at anything else a failed CPAS might do besides just make gas mileage horrible.
 

CaptainXL

Well-Known Member
Fire06 said:
Just a question i have but does the CPAS need to be changed as maintenance or just when the codes start coming?

I consider it preventative maintenance and would replace it every 100K. Given enough time the screens could fall off and the connector could leak as well. These issues have been noted by members many times here and on trailvoy.

In my book any mechanical part that gets moved often is a candidate for being labeled under the preventative maintenance category. This means replacing it and not cleaning it. You can try to clean it but it is difficult to say with any certainty that the inside is clean. I cleaned mine but decided to replace it. The vehicle actually ran better afterwards. About the only thing that can be cleaned are the screens. And that is tough to do without forcing any metal into the actuator itself.
 

Hypnotoad

Well-Known Member
Thanks for the write-up. I'm sitting at 120k miles and got the P0014 code. I cleaned the CPAS, and I immediately noticed that the throttle response is much better than before. Fingers are crossed that the code doesn't come back.
 

Fire06

Well-Known Member
CaptainXL said:
I consider it preventative maintenance and would replace it every 100K. Given enough time the screens could fall off and the connector could leak as well. These issues have been noted by members many times here and on trailvoy.

In my book any mechanical part that gets moved often is a candidate for being labeled under the preventative maintenance category. This means replacing it and not cleaning it. You can try to clean it but it is difficult to say with any certainty that the inside is clean. I cleaned mine but decided to replace it. The vehicle actually ran better afterwards. About the only thing that can be cleaned are the screens. And that is tough to do without forcing any metal into the actuator itself.

Thanks Captain I will look at replacing this spring
 

'03EXT

Active Member
Thanks for the great write up, cpas shines like the sun...what I can add is when I was looking for an old toothbrush to clean the screens I found in my medicine cabinet a little dental gum brush , it worked great on the screens much more flexible than a toothbrush any cvs or Walgreen should have them.....just my 2 cents worth
 

chatterx

Well-Known Member
Excellent how to!!! Was a nice day last last thursday so I decided to do a minor tune up to the trailblazer and try to fix some of the SES light codes. Found the mini 15 amp fuse for the secondary air injection was blown. Replaced it and it shut that code off.

Got to the camshaft code problem and found your article. Also found out how easy it was to take that belt off. Got the sensor out and the screens were covered in little debris. Cleaned it off good with carb cleaner and a toothbrush and installed it. Threw the code again but upon further inspection I found out I forgot to plug the sensor back in LOL.

Have logged about 350 miles so far and the camshaft code hasnt came back however the secondary air injection code has.
 

Jkb242

Silver Supporter
This is such a great tip and an excellent procedure to follow before simply replacing the sensor.

Thanks a million!


If your truck has been throwing a p1345 and or p0014 code these simple steps can help determine if you need to replace the actual CPAS. With my experience in this procedure I had also done an engine flush using Mobile 1 full synthetic 5w30 motor oil, cheap fram oil filter.

My truck had decided to throw the p1345 and p0014 codes after my wonderful husband added engine restorer found in wal-mart. Following my engine flush, these were the steps I took in completely eliminating both codes therefor turning off my SES light without the need to reset it.

Step 1- Disconnect your battery, I should't need pictures or instructions for this step.

Step 2- Remove your Serpentine belt

Step 3- Locate your CPAS(It is directly behind/beside your power steering pump)







Step 4- Disconnect the wiring harness that is connected to your CPAS(You can replace the harness if you would like, I didn't bother doing so as mine was in pretty decent condition)



Step 5- Remove the 3 bolts holding the power steering pump, this will allow you to push the power steering pump down and back without having to remove it entirely. Using a 13mm socket and a ratchet go through the center of the pulley to reach the 3 bolts. There is no need to remove the pulley.







Step 6- Using a 10mm socket, remove the single bolt holding the CPAS in place



Step 7- Twist the CPAS towards you and pull until it comes out. Ease of removal depends on how nasty it is around the seem. Mine took a bit of finesse, Let the oil drain from it before cleaning.

My dirty CPAS



Step 8- Remove the rubber O ring, that way the cleaner won't eat away at it.



Step 9- Using Throttle body/Carb cleaner spray and gently clean the CPAS. I used a toothbrush but BE GENTLE when cleaning the screen, you really don't want to ruin that screen or you will be looking at replacing the entire CPAS. Clean from the area where the O ring is down to the bottom of the CPAS. Again be VERY careful with that screen, I can't stress it enough. You can use a lint/fuzz free towel as well. I used an old shirt. I do not have pictures of me actually cleaning the CPAS...I only have 2 arms :biggrin: You will want to pay close attention to the circles within the screen...that is where the buildup is usually located. Take your time as always and make sure you clean it evenly all the way around.

My Clean CPAS








Reverse the steps to install your newly cleaned CPAS...and DO NOT forget the O ring you took off before cleaning.

*This procedure was done on my 2003 GMC Envoy EXT SLT*

Special Thanks to my Wonderful Husband Mat for doing most of the grunt work, his muscles are much larger than mine :wink: and of course to my lovely Phantom for throwing out these codes and teaching both my husband and I that certain products made for vehicles are not made for THIS vehicle. And to everyone here at the NATION! You all have been a huge help, I couldn't be happier being apart of such an amazing community.

And remember with all normal/abnormal vehicle maintenance take your time and be patient. And most of all don't be scared to ask questions, no matter how stupid you may think it is.
 

richphotos

Well-Known Member
ive gotta do this on mine, possibly tomorrow

The unhooking the battery, is that just a precaution or does the PCM need it?
I have a memory saver now after the hell I went through the last time I unhooked the battery, I replaced the alt and thermostat (last weekend), it works great. Will I be able to use that during this job?

Sorry for brining up this old post, but I did not want to start a new thread for a simple question.
Thanks!
 

Mooseman

Moderator
You don't have to disconnect the battery for the CPAS cleaning. It's really necessary when cleaning the throttle body.
 

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