rolinhard316

So my 2004 M6 GTO started a new bad habit. At about 60 mph with the traction control on if I try to accelerate at all the low traction light indicator will turn on and the throttle will bump on and off causing the car to shake. If I turn off the traction control I can accelerate with out any issues.

I have checked the air gap on both rear wheel speed sensors and made sure they its spec'd 1.5-2.0mm all the way around as Mitchell's OnDemand recommends. I have also checked the BCM wires and everything seemed to be okay there as well (I added plastic wrap and zip ties to make sure it wouldnt happen in the future).

I ordered a pair of wheel sensors from Amazon to see if that will fix it but I'm not convinced thats the problem as everything works fine at lower speeds.

(update) I realized after posting this initially that recently I changed the rear tires to 255/40/17 and the 245/45/17 in the front, they are only 2.7 different though. Would that throw the computer off?

Any help on this would be greatly appreciated!

Thanks!

GotToGo

Probably. Can you put the old ones back on for a test?

rolinhard316

I wish... they were thrown away a couple weeks ago at Firestone when i did the initial swap. It's not my daily drive so I didn't find out there was a problem until this last weekend. I was thinking one thing to try would be to lower the pressure in the front tires to see if that affected what speed the Low Trac light came on.

GotToGo

I'm also guessing you don't have access to a tuner to update the tune for the correct tire size.

My guess is the inbalance in the sidewall is confusing the sensors.

ViceCityPerformance

Have you checked your driveshaft? Symptoms match up. If its out of balance, at speed it will cause driveline vibrations and trip off the low traction warning

rolinhard316

My predator will allow me to change the tire size, I just didn't know if it would actually adjust for the front tires being a different size than the back.

ViceCityPerformance

Tire size wont trip that... I am running a taller and wider tire in the rear. If anything your speedometer might be a little off but it wont do that...

rolinhard316

So I did a test this morning: I dropped the Air pressure in the front tires to 20 pounds and drove it a mile or so and it was noticably better, although it would still trigger the low traction indicator at 60 mph if I floored it vs gradually accelerating. So I went ahead and dropped it to 10 pounds and the problem almost completely went away. So I am going to go ahead and say that was the issue.

After looking through Mitchell's some more I read that the low traction light is is typically only triggered if the computer detects the rear wheels are spinning faster than the front. So in the case of ViceCity I think your in the clear as you are running a taller tire not a shorter one like I am.

Anyhow thought I would update the thread for the next guy who runs into this. Thank you for your help everyone!