V2 Throttle control problem

[jwa999]

Yikes. Well good to know. I usually run my rear tires down till the canvas shows, so I am forewarned when this problem shows up due to several mm worn off the tire. Hope it won't force me to change all 4 tires at the same time!
In that case I guess one could get a second set of rims to keep slitely worn front tires around.
Never had a problem on my 2002 AWD Porsche turbo, but was thinking about a second set of wheels since in texas the annual inspection sometimes comes at a time where there's plenty of rubber left on the rears, but they won't pass.

[Razorecko]

Tire wear affecting the way a vehicle traction system works is ridiculous. The only thing tire wear will affect is how well you have traction on the street. And not start fritzing out your cars computer system.

[wait4me]

The tires are not just 5 mm different in size.

Tire size is tread x sidewall diameter. So if it is 285 40 19, the tire is 710.60MM the 285 35 19 is 682MM Which is almost an inch difference from the 2 tires.

[Hogg]

Originally Posted by bergstpg

Sorry Hogg - my bad. I miss understood what was going on.

No problem. Its all good, I hope you get your issue fixed.

peace
Hog

[bergstpg]

Cadillac service told me yesterday Cadillac Engineers think the car isn't sensing the tire size like it is suppose to - yes - they said the car is suppose to sense the tire size. The service center is waiting to hear back from the engineers on a patch of somesorts to the software/firmware. I also got Discount Tire to order the correct tire size for the car. I will wait to replace until after this issue is resolved.

[jvp]

Originally Posted by bergstpg

Cadillac service told me yesterday Cadillac Engineers think the car isn't sensing the tire size like it is suppose to - yes - they said the car is suppose to sense the tire size.

Actually, don't be too surprised by that. Starting with the C5, certain GM vehicles could correct for different tire sizes, assuming certain conditions were met. Mainly, that the rear tires were still larger in diameter than the front ones. How do they do it? Got me. But I saw it with my own eyes, several times.

Example: I used to shod my C5 with 17" Kumho R-compound tires when going to the race track. The stock rears were 18, if you remember. So, this changed the rear tire diameter a bit (about half an inch or so). Which would screw up the speedometer for.. a while.

Someone wrote a spreadsheet that allowed you to plug in rear tire diameters and RPMs for the Corvette, and figure out what the resulting vehicle speed would be. Sure enough, redlined in 4th gear, I was doing almost 147MPH (indicated) on the track. And the spreadsheet verified that same speed, given the new tire sizes and RPMs.

Somehow, the car just figured it out.

jas

[bergstpg]

The right sized tires go on tonight. I will report the result later tonight.

At the same time, Cadillac is still troubleshooting the issue at their site and will be getting back to my service center. Once this info is available - I will post as well.

[bergstpg]

Tires replaced - problem gone!!

Mean while - I am still waiting on a report from the spark plug failure and a possible update for the possible tire size monitoring.

[UAEmonster]

bergstpg ..... bro , am having the same problem now (( Check Engine )) light came on , just today .., and i cant start the car remotely .., but i can normaly start it , so what do u think is the prob ??? saprk plugs !??! plz help