chris1

Before I ask the question, here's what I've done so far. I have a FSM, and followed most of the procedures in the diagnostic section. I've replaced the modulator assembly with a known good unit, including the wiring harness, since that had some corrosion on the terminals where it connected to the modulator. All 3 relays have been tested, as well as the diode. Fuses are good. The ABS light will come on for a second or two when the ignition is turned on, then a couple of relay clicks, and then go out. It will light up when the engine is cranking, and then go out as per FSM. One of the only tests I haven't performed yet is ohming out each of the wheel sensors. I did remove the front 2, cleaned them, and re-installed them. Haven't had a chance to do the 2 rear ones yet.



Here is the question: The ABS system will not perform the self-function test at 4-5 mph; if the system is not getting 4 correct signals from each of the sensors, will that prevent the self diagnosis test from ever happening? After I get up to 7-8 mph, the ABS light will come on and stay on until the next key/ignition cycle. Not sure if the next step is to focus on the ABS main computer/controller, or possibly one or more of the wheel sensors. I guess ohming out each of the sensors might reveal more info, however I just wanted to know first what prevents the system from not performing the self-diagnosis check at the 4-5 mph range. Not even sure I can find new aftermarket sensors if I do happen to need one. Hopefully I won't have to mess around with used ones.......


Regards, Chris

Aggravated4life

Its a wheel sensor most likely.You need to clean them up and make sure they are in correct Ohms.My abs quit working correctly,and the self test stopped,when one of the sensors was bad.Cleaning can only do so much.Check all of them,not just 2.

DanZ51

I'm amazed that you were able to remove the front two (wheel sensors) without destroying them. When I removed and replaced my rear two, they put up such a fight they were destroyed in the process.

http://forums.corvetteforum.com/c4-t...s-sensors.html