09 CTS-V 6MT - Service Stabilitrak issue

[ChurchAutoTest]

Working on an 09 CTS-V manual. This is a customer we've been working with for a couple of years now. Started with basic bolt ons and has progressed now to a bigger blower, cam, heads, headers, meth injection - pretty much the works.

The car is now producing about 750 hp/750 lbs-ft at the wheels. Drivability is good, but on the dyno and on the road, at about 4000 rpm the Stabilitrak reactivates, brake torque management clamps down hard (at least on the dyno - not so bad on the road where wheelspeeds are close front to rear) and the "Service Stabilitrak" message pops up. The only way we could get it to dyno to test the fuel and timing was to pull an ABS sensor.

We've done some other CTS-Vs producing similar power, but they were all automatics which I thought would have more issues with trans management. This is the first manual car we've reached this level with. I've maxxed out all the ETC limit tables. I've even moved the test activation parameters to ranges they shouldn't reach in regular operation. I've also disabled misfire checking and pretty much any code I can think of that would cause this issue. No codes pop up, but the problem is pretty consistent.

All I can think of at this point is that we're hitting about 500g/s of airflow around 4000 rpm. This is right near the 512 g/s limit allowed in the ETC tables and if we're touching that, maybe that's the problem and might require some serious rescaling of injector, MAF and VE tables. We've had this car for way too long and I'm running out of things to try. Customer is being patient, but that can't last forever.

Does anyone have any similar experiences? I've read about lots of issues on the Trailblazer SS, but nothing like this on a CTS-V.

Thanks

[ChurchAutoTest]

Quick update. On the dyno, but not on the road, we can get the stabilitrak problem to surface at rpms lower than 4000. If we hold the car at constant rpm and gradually add throttle at, say, 3500 rpm, we can get to full power no problem. But if you aggressively ramp into the throttle it engages stabilitrak and we get a VSS sensor intermittent error code (P0503). We are also going to try going back to a stock TB as well since this error may have something to do with dyno vs. road.

[ChurchAutoTest]

Disabling VSS error code does not help. Still waiting for stock TB to arrive.

[swingtan]

Any DTC's or FF's thrown when this occurs?

[ChurchAutoTest]

It did get the VSS code, but we eliminated that. Later threw a misfire, but EFILive won't freeze frame so I plugged in a generic scan tool to check the conditions under which the misfire occurred. And I'll be damned if the problem didn't go away. Turns out that if we have the V2 plugged in to the OBD2 port while running, we kick the Stabilitrak error. If it is disconnected, car runs like a champ. I switched back and forth multiple times between the V2 and the generic scan tool and the problem reoccured and went away with the V2 connection (whether or not my laptop was connected to it). I think the codes were occurring because of some sort of ignition or signal corruption issue to the ECU when stabilitrak reactivated.

I don't know if this is an EFILive issue or a weird ground/OBD2 connector issue on the car. I'll be emailing EFILive support to let them know and see if they've had other similar issues. I'm just glad the problem is gone now. Car made 780 lbs-ft and 765 whp at 17 psi. Went out and did street testing in a variety of gears, speeds and rpms and had no issues (other than lots of wheelspin).

For future searches, I'm going to include some tags in this post to help others. Stabilitrak error, CTS-V, scan tool

[ScarabEpic22]

Huh, so when you disconnected the V2 you dont get ST kicking in? Interesting to say the least.

[Blacky]

FlashScan devices with a boot block version earlier than V2.07.01 may cause the fault you are seeing. It has been fixed in the latest V2.07.01 boot block.
Can you check/confirm which boot block version your FlashScan device is running?

You can check the boot block version on FlashScan's screen using: F4 Options -> F3 Licensing -> F1 License Details, then scroll down until you see the last section called "BOOT BLOCK".
The boot block you should have is: V2.07.01 with a date of Oct 14, 2010

Regards
Paul

[ChurchAutoTest]

Wow mine is ver 2.04.10 - 10-nov-2006

[ScarabEpic22]

Wow, update time!!

Use the V7.5 and V8 software in this post: http://forum.efilive.com/showthread....ate-2&p=140393

Im surprised it even let you do anything with an 09 CTS-V using fw that old.

[ChurchAutoTest]

I'm using a pretty recent version of 7.5 but it has never done an update of my firmware. I haven't bothered moving on to 8.x on anything yet. Is there a function somewhere in the software that does firmware updates that I'm missing?