Traction Control comes on for no reason
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Melting Slicks
Joined: Feb 2007
Posts: 3,266
Likes: 8
From: Indian Rocks Beach FL
St. Jude Donor '08-'09-'10
Your rear tires are .2 inches shorter than your front. You will continue to have TC issues as long as you run this combination.
The following is an explanation of how the system works from the service manual:
"Traction control will not have any effect on the operation of the vehicle until the control module detects one or both of the rear wheels rotating faster than the front wheels. At this time the Electronic Brake and Traction Control Module (EBTCM) will request the Powertrain Control Module (PCM) to reduce the amount of torque applied to the drive wheels. The PCM does this by retarding timing and closing the throttle. The EBTCM will apply the rear brakes, thus reducing torque to the rear wheels. Once the rear wheels begin to rotate at the same speed as the front wheels, the system will return full control to the driver. During Traction Control mode, if the brake is applied to only one rear wheel, most of the torque from the engine will be directed to the other rear wheel which will improve the traction of the vehicle."
Regarding tire sizes, again from the manual:
"The tire size is important for the performance of the ABS/TCS. The replacement tires should be the same size load range and construction as the original tires. Replace the tires in axle sets and only with tires of the same tire performance criteria specification number. Use of any other tire size or type may seriously affect ABS/TCS operation. For information on replacement tires for this vehicle, Refer to Tires and Wheels in Suspension."
The stock tire sizes give a combination of the front tire being 1 inch shorter than the rear. From all the reading I have done on the forum, as well as my own personal experience, you can get away with a 1/2 inch difference without any issues. Much less than that and you risk inappropriate activation of the system.
The following is an explanation of how the system works from the service manual:
"Traction control will not have any effect on the operation of the vehicle until the control module detects one or both of the rear wheels rotating faster than the front wheels. At this time the Electronic Brake and Traction Control Module (EBTCM) will request the Powertrain Control Module (PCM) to reduce the amount of torque applied to the drive wheels. The PCM does this by retarding timing and closing the throttle. The EBTCM will apply the rear brakes, thus reducing torque to the rear wheels. Once the rear wheels begin to rotate at the same speed as the front wheels, the system will return full control to the driver. During Traction Control mode, if the brake is applied to only one rear wheel, most of the torque from the engine will be directed to the other rear wheel which will improve the traction of the vehicle."
Regarding tire sizes, again from the manual:
"The tire size is important for the performance of the ABS/TCS. The replacement tires should be the same size load range and construction as the original tires. Replace the tires in axle sets and only with tires of the same tire performance criteria specification number. Use of any other tire size or type may seriously affect ABS/TCS operation. For information on replacement tires for this vehicle, Refer to Tires and Wheels in Suspension."
The stock tire sizes give a combination of the front tire being 1 inch shorter than the rear. From all the reading I have done on the forum, as well as my own personal experience, you can get away with a 1/2 inch difference without any issues. Much less than that and you risk inappropriate activation of the system.
Racer
Joined: Jun 2010
Posts: 457
Likes: 0
From: LaGrange Ga
Your rear tires are .2 inches shorter than your front. You will continue to have TC issues as long as you run this combination.
The following is an explanation of how the system works from the service manual:
"Traction control will not have any effect on the operation of the vehicle until the control module detects one or both of the rear wheels rotating faster than the front wheels. At this time the Electronic Brake and Traction Control Module (EBTCM) will request the Powertrain Control Module (PCM) to reduce the amount of torque applied to the drive wheels. The PCM does this by retarding timing and closing the throttle. The EBTCM will apply the rear brakes, thus reducing torque to the rear wheels. Once the rear wheels begin to rotate at the same speed as the front wheels, the system will return full control to the driver. During Traction Control mode, if the brake is applied to only one rear wheel, most of the torque from the engine will be directed to the other rear wheel which will improve the traction of the vehicle."
Regarding tire sizes, again from the manual:
"The tire size is important for the performance of the ABS/TCS. The replacement tires should be the same size load range and construction as the original tires. Replace the tires in axle sets and only with tires of the same tire performance criteria specification number. Use of any other tire size or type may seriously affect ABS/TCS operation. For information on replacement tires for this vehicle, Refer to Tires and Wheels in Suspension."
The stock tire sizes give a combination of the front tire being 1 inch shorter than the rear. From all the reading I have done on the forum, as well as my own personal experience, you can get away with a 1/2 inch difference without any issues. Much less than that and you risk inappropriate activation of the system.
The following is an explanation of how the system works from the service manual:
"Traction control will not have any effect on the operation of the vehicle until the control module detects one or both of the rear wheels rotating faster than the front wheels. At this time the Electronic Brake and Traction Control Module (EBTCM) will request the Powertrain Control Module (PCM) to reduce the amount of torque applied to the drive wheels. The PCM does this by retarding timing and closing the throttle. The EBTCM will apply the rear brakes, thus reducing torque to the rear wheels. Once the rear wheels begin to rotate at the same speed as the front wheels, the system will return full control to the driver. During Traction Control mode, if the brake is applied to only one rear wheel, most of the torque from the engine will be directed to the other rear wheel which will improve the traction of the vehicle."
Regarding tire sizes, again from the manual:
"The tire size is important for the performance of the ABS/TCS. The replacement tires should be the same size load range and construction as the original tires. Replace the tires in axle sets and only with tires of the same tire performance criteria specification number. Use of any other tire size or type may seriously affect ABS/TCS operation. For information on replacement tires for this vehicle, Refer to Tires and Wheels in Suspension."
The stock tire sizes give a combination of the front tire being 1 inch shorter than the rear. From all the reading I have done on the forum, as well as my own personal experience, you can get away with a 1/2 inch difference without any issues. Much less than that and you risk inappropriate activation of the system.
Are you talking about 1/2 inch in total tire height (diameter)?
Melting Slicks
Joined: Feb 2007
Posts: 3,266
Likes: 8
From: Indian Rocks Beach FL
St. Jude Donor '08-'09-'10
I have never heard of this being done and I don't believe a handheld tuner or even the software based programs like HP Tuners would be capable as it would require a rewrite of the firmware in the EBTCM. If it is possible I am fairly certain it would require a Tech 2 and someone willing to assume the liability issues of such a change.
Tech Contributor
Joined: Jan 2004
Posts: 20,030
Likes: 289
From: Wylie TX --> Less is More, except under the hood !
Someone did not do there homework on up sizing there tires. Sorry. but your going to have to bite the bullet on this one.
See my post on the subject:
http://forums.corvetteforum.com/c5-g...ah-issues.html
Your situation:
Stock C5 (97-04):
Front
Rim size = 17x8.5" rim
Tire Size = 245/45/17
Circumference = 2047mm
Diameter = 652mm
Rear
Rim Size = 18x9.5"
Tire Size = 275/40/18
Circumference = 2126mm
Diameter = 677mm
Front
Stock = 245/45/17 = (Circumference = 2047mm)(Diameter 652mm)
Your setup = 245/35/19 = (Circumference = 2076mm)(Diameter 661mm)
Rear
Stock = 275/40/18 = (Circumference = 2126mm)(Diameter 677mm)
Your setup = 275/30/19 = (Circumference = 2038mm)(Diameter 649mm)
Your new tire setup:
Front --> Increased the Circumference by 29mm (Diameter 5mm)
Rear --> Reduced the Circumference by 88mm (Diameter 18mm)
In summary:
When up sizing or downsizing tires you need to .... Keep both the front and rear sizing adjustments as close as possible...
Your problem above is that the the front increased in size, and your rear decreased. You just can't do that. Both front and rear MUST increase or decrease the same amount (or keep very close).
Read my post above and it will help you choose better sized tires for your rims.
PS... Many people with 19/19 combo's run 275/30-19, and 305/30-19. That's the correct sizes for your setup (see my post.)
Hope this helps
Toque
See my post on the subject:
http://forums.corvetteforum.com/c5-g...ah-issues.html
Your situation:
Stock C5 (97-04):
Front
Rim size = 17x8.5" rim
Tire Size = 245/45/17
Circumference = 2047mm
Diameter = 652mm
Rear
Rim Size = 18x9.5"
Tire Size = 275/40/18
Circumference = 2126mm
Diameter = 677mm
Front
Stock = 245/45/17 = (Circumference = 2047mm)(Diameter 652mm)
Your setup = 245/35/19 = (Circumference = 2076mm)(Diameter 661mm)
Rear
Stock = 275/40/18 = (Circumference = 2126mm)(Diameter 677mm)
Your setup = 275/30/19 = (Circumference = 2038mm)(Diameter 649mm)
Your new tire setup:
Front --> Increased the Circumference by 29mm (Diameter 5mm)
Rear --> Reduced the Circumference by 88mm (Diameter 18mm)
In summary:
When up sizing or downsizing tires you need to .... Keep both the front and rear sizing adjustments as close as possible...
Your problem above is that the the front increased in size, and your rear decreased. You just can't do that. Both front and rear MUST increase or decrease the same amount (or keep very close).
Read my post above and it will help you choose better sized tires for your rims.
PS... Many people with 19/19 combo's run 275/30-19, and 305/30-19. That's the correct sizes for your setup (see my post.)
Hope this helps
Toque
Last edited by Toque; Jul 26, 2010 at 11:17 PM.
Racer
Joined: Jun 2010
Posts: 457
Likes: 0
From: LaGrange Ga
Melting Slicks
Joined: Feb 2007
Posts: 3,266
Likes: 8
From: Indian Rocks Beach FL
St. Jude Donor '08-'09-'10
