Cobalt LSJ - boost limited to 3 psi - boost control solenoid - PID for monitoring

[Slavik]

Hi all,

I own a Cobalt SS Supercharged 2006.
The car is supposed to boost up to 80 kpa (12 psi) stock, but for some reason my boost is limited to 20 kpa (3 psi) at WOT.

Whenever I bypass the wastegate solenoid, the car boost to 12 psi at WOT without any problems.
This leaves me wondering whether it's the ECM that does not command 100% duty cycle at WOT for some reason.
Commanding 100% duty cycle shuts off that valve (allowing full boost).
By bypassing it I disable ECM control over the supercharger (I get full boost in this case).

I would like to monitor my wastegate solenoid duty cycle.
I don't own the HPTuners setup, but have a ODB reader and Torque app,
that allows to enter custom sensor PIDs to monitor.

Let me know if anyone knows the correct PID to monitor wastegate solenoid duty cycle on Cobalt SS lsj (or even LNF, it could be the same).

My intercooler pump is working, so IAT2 temps shouldn't be the reason ECM would limit the boost.
I've recently started to monitor my air intake temp after the supercharger (IAT 2, sensor PID: 222006),
and after reading over 170-180F IAT2 I realized that my intercooler pump is not working.
We've replaced the pump (I can see the intercooler fluid burbling), and now IAT2 is at the levels of 140-150F.

Thanks,
Slavik

[TCSS07]

I had to do the exact same thing to a friends lsj I tuned a few years ago. I determined it was the ecm (supplied from outside vendor in there stage kit) since I tried my solenoid and actuator to no change so when I made it run strictly off mechanical power it was fine so we just left it like that and has had no problems. I wont be by my computer to look at any logs tonight but I believe it read 100% (PID: boost solenoid control) on mine and my system works correct but ill double check tomorrow if no one else answers.

edit: Yes mine reads 100% all the time. I did a min/max histogram and there were a few spots it hit 85% but it was in the midrange. Wot was 100% all the way.

[Slavik]

Thanks for the info!

You use hptuners VCM scanner for datalogging? Can you post a picture where should I select "PID: boost solenoid control" in the software, just trying to figure out how can I monitor it without purchasing MPVI2.
Also, if it has any description for the "PID: boost solenoid control" logging, it could mention an id like PID: 222006. These PIDs can be entered into Torque android app and monitored with a simple ODB2 reader.

For example here are all the Pids for Ford vehicles (don`t work with Chevy):

https://forum.xda-developers.com/gen...3657805/page47
Wastegate Duty Cycle Commanded WGDC 220462 ((A*256)+B)/327.68 0 100 %

https://www.ecoboostperformanceforum...p?topic=3141.0
Waste Gate % Discussion occurs on page 2, and 18.
PID 220462
Equation: A/128*100

[SSKev]

Same thing happened on my 07 right before my lease was over. Electrical gremlims. Since I had warranty I left it at the dealership for 3 weeks (my friend was a service advisor). They couldn't figure it out so I just gave it back to GM like that, who never charged me anything since I left it at the dealership under warranty.

I eventually spoke to the person who bought the car after me, and GM dumped it on auction, and whoever sold it to the new person never bothered to resolve it either.

At the same time my cruise control stopped working, was that something extra on my car, or has yours stopped working?

[xxprotegexx]

Have the same issue. Solenoid at 100% all the time. Only 3psi of boost all the way to 7k. If I bypass I get all the boost. Still cant figure it out.

[SSKev]

xxprotegexx, does your cruise control still work or is that not working as well?

[TCSS07]

xxprotegexx - It isnt a big deal to just leave it like that if you want. As I stated above I tried my bypass solenoid and actuator and it didnt fix it and all that's left is the ecm so we just left it like that and his car had no issues since. Its been about 3 years now. The only real downside is now you took the ecm out so you no longer have a fail safe for if knock occurs but as long as your tune is spot on it shouldnt be a issue.

[xxprotegexx]

The cc works fine, yeah after awhile I'm kinda over it. I get zero knock under WOT. So even if I have the nipple exposed ,it just shoots out to the atmosphere correct? Not like it's a vacuum leak. And thanks for the response.

[TCSS07]

xxprotegexx - yes it would be a type of vac leak sure. its at the intake. so either get a vac cap and secure it or what i did was i removed the intake hose from the back solenoid nipple and ran a 10mm bolt in it and just tucked it out of sight

[xxprotegexx]

I have mine open at the actuator bottom nipple. The rest is plugged up. If I plug it and it struggles to get to boost. Eh it works. Lol Thanks guys

[TCSS07]

xxprotegexx - i probably should of elaborated a little more on my way but i also removed the line from the blower and capped the blower so its totally isolated but if its working for you how you have it just let it ride

[xxprotegexx]

Ohhhhhh I'm try that, see how it works. Let y'all know how it went for me. Tomorrow at least cause it's hot out here.

[cobaltssoverbooster]

has anyone else deleted the factory bypass and used a standard bov or is it just my cousins car?
he had issues with this years ago and asked me to make it run like a regular roots blower setup so i disabled the valve and welded a bov to the bottom of the manifold to act as a surge controller for decel.

[xxprotegexx]

Not fully deleted, just capped off. How did that work out for him?

[cobaltssoverbooster]

worked fine from what i was told. i made a plate to mount where the bypass valve goes and slaughtered the valve to steal the actuator rod from it. i threaded the rod and jam nutted it permanently closed in the plate. the bov did its job of controlling surge so all good there. he said it took him 2 days to street tune to how he preferred to drive. he liked the response down low that cam back due to some sort of valve failure or electronic issue. i dont know exactly what he was experiencing but after reading you guys having issues i wonder if his was doing the same thing years ago.

[xxprotegexx]

Most likely, glitch in the system. As long as they worked after the mods or bypass. Lots off ppl are quick to point out that you will run rich and your gonna spin the supercharger passed it's limits. I'm yet to see any of that.

[TCSS07]

I dont see how you would run rich with doing the bypass setup. All that happens is the ecm wont play a role in controlling boost which would be no different than just turning it all off in the tune

[cobaltssoverbooster]

we ran a harrop unit with a a wastegate on the manifold to control boost ramp in rates and just set the blower ratio to come on quick as shit while maintaining a max boost pressure at zero gate control.
we ran something like 25 psi and used the turbosmart unit to control boost. tuned the ve for launch rpm and set the maf to enable just outside the launch window so i wouldnt have to blend performance maps. these tricks have been a round way before me.

TCSS07- yeah the bypass just runs it like an old roots setup. on wherever the pulleys say it comes on.

[xxprotegexx]

Got my new WB, (aem) also went with your full isolation of the supercharger. Well I was running super rich the way I had it, with it isolated it got louder and still running rich but that's my fault. But not as rich. Long story short. No cel and feels and sound good.

[Slavik]

Hi all, thanks for chiming in!

I figured out my issue regarding no voltage on the bypass solenoid.
It turns out my PCM was swapped by the previous owner (by a repair shop, for unrelated reasons), and what was installed is a generic GM PCM, not the native LSJ PCM:
"Refurbished module for ACDelco", part: 19209822.
This PCM is marked as compatible with the following vehicles: Chevy Cobalt 2006-2007, Chevy Malibu 2006, Saturn Ion 2006-2007
https://www.carid.com/acdelco/gm-ori...-19209822.html
When ACDelco marks it as "Refurbished", they remove previous part# stickers on it, thus it's impossible to know which vehicle it was taken from.
I assume this PCM was originally installed on a Malibu, and it's software doesn't know to put any voltage on a bypass solenoid

Anyways, after installing a native LSJ PCM, 12 PSI boost is back where it should be.

SSKev:
"At the same time my cruise control stopped working, was that something extra on my car, or has yours stopped working?"
Mine is working fine, np.

Anyone got a stock SS LSJ 06/07 tune for this PCM? A couple threads have them, but the links are dead:
https://forum.hptuners.com/showthrea...LSJ-Stock-Tune