Engine randomly revs

AndyZ87 · 03-13-2020, 11:51 PM

This is for a 2016 2SS M6. I recently had to replace a wheel stud on the rear passenger side. There was quite a bit of items to remove and reinstall. Anyway since then when I drive the engine will randomly rev up and stabilitrac lights come on. Is it possible I messed up a sensor back there?

Alpha1BC · 03-14-2020, 01:39 PM

There's no weird noises or vibrations since you swapped the stud, right? Assuming no, the Stabilitrak light coming on makes me think the wheel speed sensor either wasn't hooked back up properly or got mushed during installation.

When you say "rev up," do you mean while driving? If so, sounds to me like it's activating engine drag control. Basically thinks the rear wheels are slowing down too much relative to the front so it revs the engine. This keeps the rear from sliding before the fronts on slippery surfaces due to engine drag. This also could be explained by having a damaged/intermittent wheel speed sensor signal.

If you don't have a way to check and see if there are any stored codes with an advanced scanned that can read brake module codes, I'd suggest checking out the wheel speed sensor to make sure it's properly hooked up and wasn't moved or damaged accidentally when you installed the stud.

AndyZ87 · 05-22-2020, 12:43 PM

I guess there was an important part I missed. Before i add it, i did confirm the speed sensor is in good shape and working. When I did the wheel stud I also put on a 28inch tire on a 17inch racestar. In the front I am running a 17inch race star with a 26inch tire. Could the differential in tire size be the issue? I had a buddy hook up his scanner while we drove the the front speed sensors are reporting differently from the back ones. Even if I swap on stock 20s on the front and still does it.

Mark114 · 05-22-2020, 02:19 PM

If you search there are some great threads about traction control, how the car calculates speed, and the comparison between wheel sensors and engine/transmission RPM. I believe the traction control system starts having problems when the difference between front and rear tires is 1" or more.

chaospiece · 05-23-2020, 08:54 AM

Yeah stabilitrack won't let you have too much leeway with wheel circumstance.

03-13-2020, 11:51 PM	#1
AndyZ87 Drives: 2016 2SS Join Date: Mar 2018 Location: Chicago Posts: 63	Engine randomly revs This is for a 2016 2SS M6. I recently had to replace a wheel stud on the rear passenger side. There was quite a bit of items to remove and reinstall. Anyway since then when I drive the engine will randomly rev up and stabilitrac lights come on. Is it possible I messed up a sensor back there?

03-14-2020, 01:39 PM	#2
Alpha1BC Drives: 2017 1SS 1LE Join Date: Jun 2016 Location: Detroit, MI Posts: 1,001	There's no weird noises or vibrations since you swapped the stud, right? Assuming no, the Stabilitrak light coming on makes me think the wheel speed sensor either wasn't hooked back up properly or got mushed during installation. When you say "rev up," do you mean while driving? If so, sounds to me like it's activating engine drag control. Basically thinks the rear wheels are slowing down too much relative to the front so it revs the engine. This keeps the rear from sliding before the fronts on slippery surfaces due to engine drag. This also could be explained by having a damaged/intermittent wheel speed sensor signal. If you don't have a way to check and see if there are any stored codes with an advanced scanned that can read brake module codes, I'd suggest checking out the wheel speed sensor to make sure it's properly hooked up and wasn't moved or damaged accidentally when you installed the stud. __________________ 2017 SS 1LE.

05-22-2020, 12:43 PM	#3
AndyZ87 Drives: 2016 2SS Join Date: Mar 2018 Location: Chicago Posts: 63	I guess there was an important part I missed. Before i add it, i did confirm the speed sensor is in good shape and working. When I did the wheel stud I also put on a 28inch tire on a 17inch racestar. In the front I am running a 17inch race star with a 26inch tire. Could the differential in tire size be the issue? I had a buddy hook up his scanner while we drove the the front speed sensors are reporting differently from the back ones. Even if I swap on stock 20s on the front and still does it.

05-22-2020, 02:19 PM	#4
Mark114 Drives: 2016 2SS Convertible Join Date: May 2012 Location: St. Louis, MO Posts: 1,711 View My Garage	If you search there are some great threads about traction control, how the car calculates speed, and the comparison between wheel sensors and engine/transmission RPM. I believe the traction control system starts having problems when the difference between front and rear tires is 1" or more.

05-23-2020, 08:54 AM	#5
chaospiece Drives: 2018 SS, 2016 GT Join Date: Mar 2018 Location: California Posts: 210	Yeah stabilitrack won't let you have too much leeway with wheel circumstance.

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