Hi - lurk around here often but first post.

I'm having a persistent problem with my Cobalt SS TC that nobody can seem to fix. I've taken it to the dealership at least 3 to 4 times while it was under warranty. It currently has 55k miles on it.

Basically, I'll be driving down the road and all the sudden it starts cutting out. I press the gas and it doesn't accelerate. I noticed I don't have any boost on my RPD anymore.

I pull over, turn off the car, turn it back on and then the RPD shows "Data Not Available".

Once I start driving it again, I can hear the turbo whistling but the car is lacking umph. My guess is it's put itself into limp mode at this point.

They've replaced the PCM+reflashed, the MAP sensor, cleaned the MAF sensor, and did a smoke test for a turbo leak. They even had me drive around with a recorder on it. No CEL or codes and it's insanely hard to reproduce too. It'll run like crap like this for a while and then it'll be fine for 6 months before it happens again.

I'm out of ideas and about to the point that I'm thinking of just selling it. Anyone got an ideas before I pull the plug?

Thanks

 

Well after a couple days, the check engine light came on. I ran the codes at AutoZone and it seems to be the exact same codes that others have thrown with these problems: p0101 & p0106.

After speaking with a GM mechanic, it appears that I'm not the only one with this problem and that everyone that has this problem has the GM Stage 1 Kit.

Other weirdness that happens: the car will jerk back and forth after the boost surges up and down (1 psi to 5 psi to 1 psi to 5 psi)

None of the threads I've read (including a Solstice thread) have found the solution. I'm about ready to tell GM to buy my car back at this point.

 

Does it cut in and out when your in boost? Have they looked at the plugs? No sure why the RPD says no data, not familar with the rpd

 

No, it's not during boost. It usually happens at a constant speed but it happen again this morning while accelerating lightly from a stop light.

For instance, I'll be driving on the freeway at a constant speed of 70 mph with cruise control and then all the sudden it will cut out, drop a mph or two and then come back. It'd be like if I hit the brake for a quick second and then resumed at the same speed.

I will check if they've looked at the plugs since I'm not sure.

RPD = Reconfigurable Performance Display

 

Ok so I'm going to say it's about an 80% chance of being a dirty or bad map sensor.

Start by cleaning the one on the manifold. Then one on the lower charge pipe.

make sure you have the correct color o-rings on the sensors

The reason it says No Data is because it's losing connection to the MAP sensor and can't read boost or temp.

Again dirty or bad MAP sensor.

Good Luck

 

I don't think it matters but snapped a few photos this morning while driving.

Here's the check engine light (CEL) + No Data Available from this morning

https://www.dropbox.com/s/6uo680ufgw...2008.21.27.jpg

Here's an up close of the No Data Available

https://www.dropbox.com/s/c0g4v2gklx...2008.03.27.jpg

CEL and No Data Available will be on for a little while and then they'll turn off and go back to normal. The next day they might show up or it might be 6 months before they show up again.

 

umrdyldo - thanks. I definitely think it's something with the MAP sensor too. What I wanna know is why it keeps failing though (since they've replaced it before)?

If it's getting dirty, is there something I can do to shield it?

 

Oh and to answer your other question: "make sure you have the correct color o-rings on the sensors" <-- I did have them check this and yes they're the correct o-rings.

 

Well if it's blow by getting them dirty then you would need the Powell PCV separation setup. But I can't imagine you have so much blow by of oil that it is ruining them that quickly, but who knows. I'd try cleaning first. I have never cleaned mine in 5 years.

 

You have the GMS1 kit and the wires were not soldered on well, crimped properly, or otherwise attached in such a way as to prevent voltage loss. Go over the wiring for the two sensors and fix them.



reference:

https://www.cobaltss.net/forums/2-0l...ilable-256673/
https://www.cobaltss.net/forums/2-0l...ilable-282898/

 

Dealer/Mechanic that installed it has checked the connections several times.

 

Based on past forums posts, it seems like everyone that has a GMS1 kit has replaced their MAP sensor ... 1 or more times. That or they clean it every month.

The issue goes away for a bit and it's back. I feel like this is a GM problem. Sigh.

I can have them replace/clean the MAP but it seems temporary - I want GM to figure out the real issue.

 

That's simply just not true.

I have the GMS1 sensors, but with the plug and play connectors, not the solder on ones. I've got no RPD, but I've had zero issues with these sensors losing connectivity in the over a year I've had these sensors on the car. A lot of people with the solder/crimp on kit have had issues. But far from ALL.

The dealer/mechanic that put them in found no issues. Have YOU looked at them? Had someone else look at them?

 

Have you had all the recalls done? i know it sounds like something the dealer should'nt miss.

 

Sox-Fan - Thanks for the reply. Not everyone that has GMS1 has the issue, you're right, but I feel like it's a common enough problem that it may be worth considering that it's a GM issue.

No, I have not looked at them personally. I trusted the mechanic that did it since I've never had any reason not to trust him. I'll inspect them personally.

Plug and play connectors sound like a promising way to rule out a wire issue. I didn't even know they existed.

 

Gobolt210 - I had one recall done right after I bought the car, new. I can't remember what it was for now. I'll check my VIN.

 

Plug and play connectors may not be an option for you anymore if the installing tech cut the plugs off of the wiring harness.

 

Its not a GM problem if the dealers can't install them correctly, most likely the issue is unqualified ppl doing the sodering is the issue.

I knew what rpd stood for, just don't have one nor had heard of anyone having issues, but from other responses issues are map related

 

Just remember if you're MAP is giving signals that make no sense compared to the MAF it may throw a MAF code making you think the issue is there. You can clean that MAF a million times but it's not going to help if your MAP is not getting the right readings to the ECM. A bad crimp connector or bad solder will be hard to see but will easily give your ECM problems.

 

Thanks everyone - hopefully report back soon.

 

Following up on this: all the wires I checked were crimped + heat shrinked and looked ok to me. Also cleaned the MAP sensors with no luck.

After speaking with the mechanic, they had a dialog with GM Engineering and it was suggested that the connections be soldered on. At least for now, the issue appears to be gone. I'm skeptical though ... guess we'll wait and see. Wish I would have got the plug and play kit. Sounds like it came out just after I got mine installed.

 

OP I'm having the exact same issue as you right now. I have a 2010 SS/TC with the GMS1 kit installed.

About a week ago I got the Data Not Available message and a CEL. Both went away a few days after then came back on again.

Yesterday my car started driving weird. The CEL is still on but the RPD is actually showing the boost gauge. When I start accelerating under light throttle, I can see that the turbo tries boosting a bit, then cuts out, then tries boosting a bit more, then cuts out again so when I'm driving normally, it feels jerky. If I actually want to accelerate quickly, the boost seems to work fine, it's just an issue when you apply light pressure on the throttle.

I haven't done any troubleshooting yet and I've dropped it off at the dealership. They've called me earlier and said that they couldn't find any issues with the sensors even though the CEL was indicating so they're not sure what the problem is. This doesn't make sense to me since it's clearly the sensors in that case. They're still trying to reproduce the problem and will get back to me later today.

I'll keep this thread updated with what I find. If the dealership won't be able to resolve this, I'll clean/replace the sensors first and then go from there.

 

Crimp on connectors do not last. Period. They corrode, they lose voltage. In a word, they suck.


You've read all of the posts above and came out thinking you have dirty sensors?

Make sure the sensors have the correct black o-rings, not green. Green will eventually leak and cause your car to throw a MAF code. Make sure that all of the connections are conducting properly. If the MAP connections are not conducting well you get the loss of data error. If they are conducting, but losing voltage then your car cannot resolve what the MAF and MAP are telling it and will throw a MAF code. It has no way to know which is wrong, so by default it blames the MAF.

I can't remember ever seeing many MAPs go bad, if at all. I've seen lots and lots of crappy crimp connectors slowly go bad.

 

Hopefully soldering your connections resolved your issue boardin, but just as a heads up to you and anyone else with this issue, just "looking" at the crimp will tell you absolutely nothing about what is actually happening with the connection within the butt connectors themselves. Someone well versed in using a high resolution multimeter (preferably a scope) needs to check and graph the voltage feed, ground and signal output to and from the map sensors (especially the lower sensor) in front of and after the splice and check for any spikes or dips in voltage and/or high/low resistance or changes while wiggling the connections. What's likely happening isn't an issue with the tune or hardware (although the sensor can of course fail). It's more likely an issue from within the splice that happens at random from either temp changes, bumps or even torsional movement from the engine torqueing. I have even seen a random short to ground issue due to over tightened crimp connections which caused the shrink boot to tear slightly. Once the boot tears and is then heat shrunk, this exacerbates the tear and causes it to grow. The now exposed metal in the connector could randomly short to ground accidentally and cause the ecm to cut all boost.

I can't say for sure that this is or was absolutely your issue, but it is very possible. I will say however that I have personally never had a gms1 sensor fail on my personal vehicle in the past 1.5 years or so that I've been running the 3bar sensors, along with any vehicles I have tuned with the 3bar sensors who have used the plug and play connectors. Point is, crappy connections/splices can also damage and destroy hardware.

 

I have tuned quite a few guys here lately with these issues as well lots of 3 bar maps either going bad or ending up with bad connections here lately.