My Active Handling/ABS Warning Light came on and I pulled this code C1225 H (RF Excessive Wheel Speed Variation). I knows its a history code and i cleared it a couple times. I put some different wheels and tires on can that have anything to do with that code. The tire sizes are 255/35/18 front and 295/30/19 rears. Could this be a sensor or somthing? Thankyou in advance

 

1999 Chevrolet Corvette V8-5.7L VIN G
Vehicle Level Powertrain Management Computers and Control Systems Testing and Inspection Diagnostic Trouble Code Tests and Associated Procedures C Code Charts C1225

DTC C1225 LF EXCESSIVE WHEEL SPEED VARIATION


CIRCUIT DESCRIPTION
The speed sensor used on this vehicle is a single point magnetic pickup. This sensor produces an AC signal that the Electronic Brake and Traction Control Module (EBTCM) uses the frequency from to calculate the wheel speed.

CONDITIONS FOR SETTING THE DTC
The Diagnostic Trouble Code (DTC) can be set anytime the brake is not depressed and no wheel speed sensor hardware DTCs are present, and the Electronic Brake and Traction Control Module (EBTCM) sees a wheel speed variation of more than 14 Km/h (9 mph) for 2.5 seconds.

ACTION TAKEN WHEN THE DTC SETS
ABS/TCS/Active Handling (if equipped with RPO JL4) are disabled.


Indicators that turn on:
ABS indicator
Car Icon (TCS indicator)
Messages displayed on the Driver Information Center (DIC) :
Service ABS
Service Traction System
Service Active HNDLG (if equipped with Active Handling RPO JL4)
CONDITIONS FOR CLEARING THE DTC


Condition for Diagnostic Trouble Code (DTC) is no longer present and Scan tool clear DTC function is used.
Fifty ignition cycles have passed with no DTCs detected.
DIAGNOSTIC AIDS


It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
An intermittent malfunction can be caused by poor connections, broken insulation, or a wire that is broken inside the insulation.
If an intermittent malfunction exists refer to Testing for Electrical Intermittents in Diagnostic Aids.
TEST DESCRIPTION
The numbers below refer to step numbers on the diagnostic table.


Checks the resistance of the Wheel Speed Sensor (WSS) .
Checks if the WSS CKTs are shorted together.



DTC C1225 LF EXCESSIVE WHEEL SPEED VARIATION

 

Yup, it can be the sensor and wheel circumfrance can affect it also.

Wheels, Im not a wheel guy, but the main thing is that you have to maintain a similar gradient in the circumfrance of the front tires v. the rears as the stock (17/18) set up, or you'll have AH/TC problems. It appears to me that you did that (18/19) but someone will chime in if the sidewall height your using is out of the range to keep it happy. (I doubt this is it)

The sensor can be bad (there is one on each hub) but it could also just be a dirty connection. You dont even have to raise the car to get at them (although it does make it a lot easier). Just look for a wire loom with a snap on connector at the inside of the hub. Disconnect it, clean it up with some contact cleaner, add a little di-electric tune up grease to keep corrosion at bay and reconnect it. May help.

Good luck

 

Just remember that your tires are within the stock tire height by 1/2" you are fine (I even think it is 3/4") and I believe you are well within that range with your current set-up!

There is a TECH sticky, it is long, but well worth the the read - you can check your sensor and clean the connections, all the instructions are there:
http://forums.corvetteforum.com/c5-t...tion-long.html

Thanks,Matt

 

According to this calculator those sizes are almost a full inch in diameter different.

http://www.1010tires.com/TireSizeCal...?action=submit

 

My Traction control comes on it seems whenever it wants. I could just be traveling 40mph in traffic and it engages. My rear tires are 275/35-18 Toyo Proxis which are 25.58 overall diameter vs. 26.66 for the stock 275/40-18. The sidewalls are 3.79 vs. 4.33 stock and the circumferance is 80.36 vs. 83.76 stock. Do you think this is the cause?

 

bump? having same issue for months. very intermittent, tc comes on, cuts throttle, randomly. mostly in wet conditions. but also in dry, clear roads, not traveling that fast. Anybody seen this?

 

This is an old thread, but will leave this open to see if someone can assist touring2 with the problem.

 

I had this problem, put new Conti Extreme contacts on in the stock size replacing some older Toyo's that were a slightly different size and haven't had the problem in the last 8 months.

 

I had the problem a year or two back
I unplugged the wires to the ebcm, cleaned and di-electric greased the connections
plugged them back in and have'nt had a problem since
ymmv

 

thanks all for input. Haven't read this post in a long time, my apologies to those of you took the time. went to track last weekend, plagued by ice mode. Had one clean lap where i tapped the brake with left foot to reset ice mode, just in case, and set a fastest lap, for me. LOL code, 1233, 1225 and 1247. checked RF wheel sensor, 1.04 Kohm, and voltage generates when I spin the rotor. Checked interconnect cable, got same results. thantks Vetteman and sloopdawg. going to check the grounds comb behind headlight, and EBCM conns.

 

NO. I ran 315/30/18s on the rear for years, combined with stock front tire size. Never had any issues. I'm now running 285/40/18 rears, w/stock sized fronts with no issues. 285/40s=26.98" diameter, and 315/30=25.44" diameter. Hope this helps eliminate that worry.....