My car ('99 FRC) had the "common" ABS/AH lights come on...

I checked the codes. Cleared them and they came back after driving a short distance.

Any of you have suggestions or comments, I'm willing to listen!

These are the codes that showed back up:

28-TCS
C1233 H -RF Wheel Speed Circuit Open or Shorted

B0-RFA
None since reset!

Any suggestions on where to look or what to check out for this code? I'm not really super experienced with troubleshooting Corvettes ...but I have access to a shop and am willing to check out anything ya'll think it could be!

 

Most likely 2 problems. Bad wheel sensor and poor ground(s).

 

Okay...that's a start. But if that is the case, where do you start with troubleshooting something like that?

 

The manual says if the ABS indicator is on when it's damp, inspect the wheel speed sensor wiring for signs of water intrusion.

HTH

 

It can also happen from doing burn outs.

What happens is the front wheel sensor is not reading while the rear is reading movement!

This is quite common on the Dyno where the fron tires/wheels are motionless and the rears are operating on the Dyno!

But just incase check your connections and don't burn too much rubber or we will see you asking about which brand of tire to go with!

Thanks,Matt

 

just a note, I worked on a customers vette a few weeks ago and his had the Ah/ABS lights on and I replaced the RF wheel sensor and all lights and codes are gone. Problem is, I wasnt trying to get rid of the lights or codes.....Its making a subtle whinning noise that i cant seem to hunt down

 

You clean the grounds, and inspect the wheel the code is beefing about to see if the ABS sensor is OK and check the weather pack connection-it's not rocket science. There are TONS of threads about the C5 grounds (the SEARCH function at the top is your FRIEND).

Modern cars are complex BUT the basics still apply, check the grounds and the connections FIRST, then dig deeper.

 

The wheel speed circuit is a discrete circuit and doesn't really have any so called grounds associated with each sensor. The wheel bearings/sensors are pretty much bullet proof and seldom CAUSE this issue. Unless the wires or connector on the sensor its self are damaged, it is most likely good. You can test the continuity of the sensor with an ohm meter. It should read 850-1350 ohms.

You can also jack the wheel up, spin the wheel and read the OUTPUT of the sensor with an AC Voltmeter. It will read in AC Millivolts and the output will increase with wheel speed.





The bearing will fail before the sensor. There really isn't much to them:



The most common cause of wheel speed sensor DTCs are bad connections! The "FRONT" wheel sensors connect to the chassis harness through a "JUMPER HARNESS" :



The problem 90% of the time the problem is caused by a poor connection due to defective female pins in the jumper harness or the chassis connector:





Here is an example of a good and BAD connector. The one on the left ie NEW!



To properly test the female connections and take the guess work out of the equation, you need to find a spare MALE pin and insert it into the female pins. It they don't grip the male pin properly, replace the female pin or the connector. Here is a male pin that I use. Its out of an old switch:



You can swap the left and right jumper harnesses around to see if the problem switches sides but, if you don't check the female pin, you will chase your tail for weeks!

The female male pin is good if you have to use a little effort to extract it from the female pin. If it comes out without any force, thats the problem.



BC