I keep getting a code C1226 as soon as I hit 90-95mph which I know is a wheel sensor or wiring harness issue. I don't normally drive that fast especially up here around Milwaukee. But I would like to get it fixed in case I get to go to HPDE sometime.

I checked the RF sensor harness by borrowing my friends harness and running the car with his harness up to 100mph and no code. I order a new harness and replaced what I thought was my bad harness. 3 days later I get the code again (when I lived in GA there were plenty of roads to test it on). I'm going to check my grounds after reading the electrical thread and my left wiring harness also. Is there a way to check the actual sensor in the hub?

Also, I have found 2 different lists of codes - one has C1226 as the RF wheel speed sensor and the other has it as the Left.

Does anyone know for sure which one is correct? I would like to email the site that has the wrong one and let them know.

 

Here's some info I received from Bill Dearborn about this on my 99 vette:


Hi Bill, I thought I'd ask u this one since I'm confused! I have a C1225 code for a excessive wheel speed variation after I had my ss brake lines put on. I have a fix for it, but two websites tell me different things. One says it's the left front, another says it's the right front. So, which is correct?

Here are the two websites if u would like to look:

http://myweb.accessus.net/~090/dtcobd2c.html#cha

http://www.stengel.net/diccodes.htm


I looked at the corvette doctor one, and it just gives a general range of 1225-123- = wheel speed sensors. Therefore, not too helpful.

Thanks for your valued input!



Answer:

The Service Manuals from 97 through 00 show it as the Left Front. From 01 forward they group the 4 codes together and do not define which wheel. Not sure what the significance is but the ABS/TC/AH programming changed with the 01 model year so they may have decided the definition of which wheel sensor had the erroneous reading was misleading. 2000 was the last year that AH was optional so the code could have been meant for a non-AH car.

This is what the 97 -00 Service Manuals have on the code:

Circuit Description
The speed sensor used on this vehicle is a single point magnetic pickup. This sensor produces an AC signal that the EBCM uses the frequency from to calculate the wheel speed.

Conditions for Setting the DTC
The DTC can be set anytime the brake is not depressed and no wheel speed sensor hardware DTCs are present, and the EBCM 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 DIC:
Service ABS
Service Traction System
Service Active HNDLG (if equipped with Active Handling RPO JL4)
Conditions for Clearing the DTC
Condition for 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 Intermittents and Poor Connections in Wiring Systems.
Here is what the 01 and newer Service Manuals have on the code:

C1225 through C1228
The EBCM detects a rapid variation in the wheel speed. The wheel speed changes by 16 km/h (10 mph) or more in 0.01 second. The change must occur 3 times with no more than 0.2 seconds between occurrences.

C1225 through C1228
A possible cause of this DTC is electrical noise on the wheel speed sensor harness wiring. Electrical noise could result from the wheel speed sensor wires being routed to close to high energy ignition system components, such as spark plug wires.
Hope this helps.

Bill

 

Also, here is a post about this same code from SS brake lines:

http://forums.corvetteforum.com/show....php?t=1564131

 

1226 is definitely right side. If the harness is good, no cuts or kinks, then you need to replace the bearing.

SS lines are unneccessary, and may/may not cause electrical issues in ABS cars. I recommend staying away from them in steet cars. Just isn't worth it.

 

Thanks everyone.

Does anyone know a way to test the sensor in the hub? I have new brakes waiting to go on and I could go ahead and replace the hub at the same time. I saw a post on testing it somewhere last week but can't seem to find it anymore.

 

Spin the wheel.
Use a Digital Multimeter (with 10 Megohm input impedance) to measure the AC voltage across the wheel speed sensor. If the AC voltage measures greater than 100 mV the sensor is OK.

Bill

 

Thanks Bill ande everyone else for the replies.

 

Check the female pins at both ends of the front passenger side harness.



The connector on the left is new.

 

I had the same problem when I installed SS brake lines, 3 years ago. (2000 vette) RF speed sensor. I grounded and shielded the SS line and it hasn't come back in 3 years. Unfortunately, when it happened 3 years ago, the error shuts off the ABS, and I surely needed it when I hit another car that pulled out in front of me. ABS would have stopped my car in time, but.........
I would let you know how I grounded mine, but it is not very "professional", but like I said, it works for me.
If you are interested, PM me.
Robi