Dan Wendling

I was at Watkins Glen last weekend and after a few hard laps I experienced brake fade and alternating Service Active Handling and Service Traction Control alarms in the DIC. I kept putting in laps and then noticed the brake fade got much worse to the point of no pedal at all.

I was initially running in Competition Mode but later tried Traction Control Off Mode. Did not seem to make any difference, alarms and fade happened in both modes.

The alarms stop after the ignition is cycled to off and on.

The brake fade seems to go away after the system cools down, perhaps it does not return to 100% as one gets a little phobic about the brakes once something goes wrong.

Car is a described in the signature, note I do not have a brake hose kit installed.

So my questions are:

Are the alarms and the brake fade related?

Could one be causing the other, for example if I had something wrong with my stability control system could it be trying to help me out and causing the brakes to overheat and then fail to operate correctly?

Bill Dearborn

It sounds like the stability control was operating at some level while you were on track which would tend to generate more heat than just normal braking. That could cause the front brake fluid to boil or the pads to overheat. If you were overheating the fluid in both front calipers due to excessive use of the AH you could have a complete loss of braking with the dual diagonal braking system that has implemented on C5s and C6s since 2001.

The only way to know what the messages were about is to have the ABS codes checked to see if there are any history codes.

I know you didn't have TC on but one of its operations is to monitor how long the rear brakes are being applied during a TC activation and display a message when they are in danger of overheating. The Theory of Operation doesn't mention a similar action for AH but that doesn't mean the system doesn't do the same thing. Tech Writers only work with the info given to them and rarely really understand what they are writing about so Theories of Operation are often confusing or inaccurate.

Check the ABS codes and see if they provide any insight. You need a scanner that can read the codes.

Bill

froggy47

What brake fluid, if it's stock get rid of it.

thumbs:

TKOGTO

I got those DIC messages when my pads wore down (part of your fade perhaps). Dealer erroneously added fluid. I put new pads in, bled and messages went away.

Dan Wendling

I am running Motul RBF600, bled the brakes before the event and again after the first day.

Running Toyo R888 305-35 and 335-30 x 18 so tire diameters are very close to OEM.

TPMS is fine

...

Will take to dealer to pull codes I cant see with my HP Tuner.