get the service manual. the procedure for testing the sensors is pretty thorough.

 

There is absolutely no reason for a pedal box on a street car. If the brake system is designed properly on a pedal box system, the pedal won't move. In racing, you're supposed to modulate pedal force, NOT pedal movement. Thats why the brake pedal doesn't move in a pedal box system.

Anyways, i hope you solve your problem. It sounds really dangerous. Hopefully its not something that all evo's could be plagued with. Keep us updated

 

who is talking here, about street cars?
What do you mean the brake pedal won't move in the pedal box system?

 

I grabbed the Evo 9 manual and the above is correct (for once).

Attached is pin-out for the B109 connector on the ABS ECU.

 

A few months late but what was the verdict???

 

I think he is still fighting this issue.

 

I'm convinced its a front abs sensor. Id like to borrow a known good one to test with.....

The sensors pass inspection when the car is not moving but I don't know how to log them while deep into triple digit speeds.

All problems are solved after pulling the abs fuse so that eliminates pretty much everything else. Its an abs issue for sure.

Best place to buy a new sensor???

 

What is the cleaning procedure for wheel speed sensors and ABS?

 

I simply unbolted the sensor, used a vise grips to wiggle it out of its position, then I wiped down the senor and used high pressure air to clean the abs spindle. I have one new front and rear sensor on the way. Hoping that a replacement will correct the issue.

 

^ basically the same thing I did.

Removed the front sensors, cleaned them off and blew compressed air all over the ABS ring and sensor to remove any particulates that might cause funky readings.

For the rear, since I couldn't remove the sensors, I just blew compressed air where the sensor meets the ABS ring and spun the wheel around to make sure I didn't miss anything.

 

FWIW, I had a wheel speed sensor fail on me some time ago. The car had intermittent 3 ACD lights on the car, till one day, it would keep on coming back. We hooked it up to an OBD2 computer, which had a way to monitor the speeds that are being reported by the wheel speed sensors...and at speed, we clearly saw that one sensor was reporting the wrong speed, and then the 3 ACD lights popped up. Replaced it and now its all good.

Recently, I also had a similar problem with my EVO. The high speed braking would instantly trigger the ABS, and my stopping distance almost doubles. No ACD lights this time though. I initially thought it was because I moved from A048 back to Stock EVO X tires, that are slippery...but I have my doubts that it is tire related.

Hope you've had luck with your issues...do let us know how you resolved it!

Will removing the ABS fuse, disable ACD and AYC functions?

 

I ended finding three damaged abs ring gear teeth. Looked like the axle had been dropped on the ring. I replaced the axle and the problem has been eliminated. Never did get any indication or code from the ecu.

I suspect that pulling the fuse disables all the fancy stuff.

 

Thanks! Did you ever get 3 ACD lights ?

 

No everything appeared to be normal less the lack of stopping power and stiff pedal.