I have a 97 coupe and the other day I came up on a stop sign too fast and when I hit the brakes the antilock brake light message came up and then went away. Then when I was going down hill and into a curve I stepped on the brakes and it felt like I could feel them thru the floor as well as the steering wheel wanting to jump out of my hand. It only did it once. It was like my tires were bouncing on the pavment. Now when I go to stop it feels like the rotors are warped. I am not a mechanic and I am learning as I go. Any ideas as to what the problem might be. Thanks in advanve for your advice and info.

 

DID YOU PULL YOUR CODES? IF NOT TRY THIS SITE

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

THEN POST YOUR CODES HERE SO SOMEONE CAN STEER YOU IN THE RIGHT DIRECTION. MAKE SURE THAT ANY CODES YOU FIND ARE POSTED WITH THE LETTERS THAT FOLLOW THEM, SUCH AS "C" OR "H" OR "HC." GOOD LUCK.

 

You might have cracked a rotor, and I'm thinking that would be the nicer of some of the options. I would hope its not something electronic or electromechanical. Either way, when it's brakes it pays to deal with it soon.

 

Trying to stay on the brighter side of possibilities, it is normal to feel a pulse (even a hard one) when the ABS system activates, and you will feel this through the steering wheel as well.

The feeling that you say is like the rotors are warped could be a stuck caliper. Jamming the brakes hard enough to activate the ABS could result in one or more of the calipers getting stuck in the closed position. I'd take a look at them soon to prevent warped rotors.

Either way, Fritz is right, pull your codes and post them so we can see what's going on.

 

Thanks for the info. I will chedk the calipers. I know the feeling of the ABS. This lasted 2/3 seconda and almost jerked the wheel from my hands. It was loud. I will post codes shortly

 

Here are the codes you can click on the pic too
10-PCM P1571H
28-TCS NO CODES
38-RTD NO COMM.
40-BCM NO CODES
60-1PC B0521H
60-1FC U1160H
80-RADIO U1016H
99 HVAC NO CODES
AO-LDCM U1064H
A1-RDCM U1064H
A6-SCM U1016H
BO-RFA NO CODES
NO MORE CODES
MANUAL DIAGNOSTICS 1 CODES
Looks like all the codes are history. How do you delete/reset so those codes are gone. Or do you want them there

 

You can clear your DTCs by pressing and HOLDING the reset button down in each module when you in the manual code reading mode!

When you press the brakes hard enough to lock up a wheel/sthe ABS module will take over and modulate the braking on that wheel/s to prevent wheel lock up. It will PLUSE the brakes to control traction on the wheel/s and YES, you will feel it in your seat or the steering wheel or BOTH depending on what wheel/s loose traction/skid.

When the ABS system is ACTIVE,, YES,,, you will see a DIC message saying ABS SYSTEM ACTIVE.

ABS/AH/TC Operation is covered FULLY in your owners manual!!!!!!!! ITs a MUST/SHOULD READ topic!

Heres a task for you. The next rainey day,, find a nice big EMPTY parking lot or a safe stretch of road and run the car up to say,,, 40 mph and apply the brakes HARD!!!!! That will allow you to do a controlled ABS assisted STOP!

When the roads are wet, it allows you to test the ABS System easier and does not put as much wear and tear on the suspension / tires or brakes.


READING YOUR Engine Diagnostic Trouble Codes (DTC)

This procedure should be carried out any time you experience a problem with your C5. Most inexpensive store bought aftermarket code readers will ONLY read power train DTC’s. Reading the DTC’s with the C5 built in code reader will allow you to read ALL the modules in the vehicle.

The Diagnostic Display Mode is entered with the following procedure:
1) Turn on the ignition but don't start the engine.
2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold the OPTIONS button
4) While holding OPTIONS, press FUEL button four times within a 10 -second period.

Initially, the on-board diagnostics go into an Automatic Mode which will cycle through each module and shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each module. ( i.e. PCM = 4 codes) If none are present in a given module, you will see No More Codes on the display.

There are two types of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current code indicates a malfunction is present in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes. More likely it's an indication of an intermittent malfunction.

Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.

Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except E/M. Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press RESET To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles. There are a few body module DTC’s that if set will prevent the module from operating properly. Once the DTC is cleared, the module will return to full function. This is not true for power train DTCs.

If you have never read and cleared your codes, there will probably be a lot of old history DTCs. It is recommended that you clear your codes and see if any come back during a driving cycle. Those are the ones that you need to concentrate on diagnosing.

Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5.

You can read the DTCs while the engine is running. If you turn the engine OFF and then back ON, that can clear some DTCs that may be important with identifying a problem. One example is a Misfire DTC (p-0300) If the engine is shut down, the DTC will clear.

These are some very good C5 Diagnostic Trouble Code (DTC) explanation web sites!!! They also explain how to read the DTCs

Here are some very good sites that explain what DTC mean:

http://www.gearchatter.com/viewtopic11755.php

http://www.obd-codes.com/trouble_cod...d-ii-codes.php

Make sure to include the H or C suffix when you post your DTCs!!





BC

 

Sounds like a you warped a rotor or two. ABS activation was normal.

Depending on the age of the rotors and weather or not they have been machined during a prior brake service, they can sometimes warp or crack.

Based on the steering wheel shake while braking, I would guess that you need two new front rotors. It would be good to inspect all of your brake pads as well to determine if they need to be replaced as well.

Clear all your dtc's, there are none pertinent to your ABS system. See if any come back and address those issues.

Don't forget to study that owner's manual. It is a wealth of excellent information about your car. And this forum is also a valuable source of 'things to know'

HTH

 

I too noticed that NONE of the DTCs are related to the ABS system,,, HOWEVER,,,,, some DTCs related to the EBTCM get cleared when you turn OFF the ignition.

If you ever see a Message related to the Active Handling System or have abnormal antilock brake system issues... or want to know if you have any DTCs that get cleared when you turn OFF the ignition READ THE DTCs before you turn OFF the ignition.

I also noticed in the video that you had RDT (Real Time Dampening NO COMMS. Do you have the F-45 Real time Dampening Option??? Is it functional. What have you done to troubleshoot the issue??
BC

 

Thanks Bill. Those are my codes above. I used my GOPRO and filmed it so I could stop it and get all the codes. Lookd like all mine were history and I didn't think any had t6o do with the brakes. Thanks again for all the info.

 

Thanks for your help and info. The front rotors were less than a year old but cheap ones. The rears are the originals. I will be reading the manual from cover to cover.

 

I don't have that option. I don't have anything to select my ride, touring, sport etc. Is that why I have that no comms code.

 

Make sure to check the calipers for sticking as I mentioned above as a possible root cause. A stuck caliper can cause warping. Ask me how I know.

P.S. If it is a stuck caliper and you decide to rebuild, get an order in quickly. When I checked a few weeks ago on the time frame to get rebuild kits I was looking at more than a week to get them to my house. Evidently they are nearly as rare as a purple Vette....

 

Don't want to hijack but just took off a complete set of front brakes from my 2000 yesterday. I upgraded the whole system, ss lines, powder coated brackets and calipers, and rotors. They were working just fine when taken off just wanted upgrade. If you are interested. Btw i have abs/tc/ah on my vette and had no problems/codes, etc. Before brake change.

 

Well your BCm thinks that you have the option. Do you ever get any DIC Messages for real time dampening???

You do know that you can immediately press the OPTIONS button when you go into code reading and it will go directly into manual mode. When you are in manual mode use the fuel and gages buttons to tohggle thru the codes.

" Manual mode can also be entered during the automatic sequence by pressing any button except E/M. Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press RESET To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules."


Read this:

READING YOUR Engine Diagnostic Trouble Codes (DTC)

This procedure should be carried out any time you experience a problem with your C5. Most inexpensive store bought aftermarket code readers will ONLY read power train DTC’s. Reading the DTC’s with the C5 built in code reader will allow you to read ALL the modules in the vehicle.

The Diagnostic Display Mode is entered with the following procedure:
1) Turn on the ignition but don't start the engine.
2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold the OPTIONS button
4) While holding OPTIONS, press FUEL button four times within a 10 -second period.

Initially, the on-board diagnostics go into an Automatic Mode which will cycle through each module and shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each module. ( i.e. PCM = 4 codes) If none are present in a given module, you will see No More Codes on the display.

There are two types of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current code indicates a malfunction is present in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes. More likely it's an indication of an intermittent malfunction.

Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.

Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except E/M. Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press RESET To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles. There are a few body module DTC’s that if set will prevent the module from operating properly. Once the DTC is cleared, the module will return to full function. This is not true for power train DTCs.

If you have never read and cleared your codes, there will probably be a lot of old history DTCs. It is recommended that you clear your codes and see if any come back during a driving cycle. Those are the ones that you need to concentrate on diagnosing.

Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5.

You can read the DTCs while the engine is running. If you turn the engine OFF and then back ON, that can clear some DTCs that may be important with identifying a problem. One example is a Misfire DTC (p-0300) If the engine is shut down, the DTC will clear.

These are some very good C5 Diagnostic Trouble Code (DTC) explanation web sites!!! They also explain how to read the DTCs

Here are some very good sites that explain what DTC mean:

http://www.gearchatter.com/viewtopic11755.php

http://www.obd-codes.com/trouble_cod...d-ii-codes.php

Make sure to include the H or C suffix when you post your DTCs!!

 

[QUOTE=Bill Curlee;1581704401]Well your BCm thinks that you have the option. Do you ever get any DIC Messages for real time dampening???


Why would the BCM think I have that option. Is there a way to tell if it was there at one time and removed. I have never got a DIC message for RTD. I also pulled the codes with the car running this time and the codes are identical.

I searched the DIY sticky for rebuilding the calipers and did not fine one in there. Is there some other place I should look.

 

This is a very good write-up by Wilwood on how to rebuild calipers. Wilwood calipers have more pistons than stock Corvette, but the process is basically the same. I can't stress enough to make sure you wear protective goggles and gloves when disassembling the calipers unless you enjoy brake fluid in your eyes and crushed fingers, and also be sure to insert a block of wood or something similar between the pistons and caliper frame when applying the compressed air.

http://wilwood.com/Pdf/howtostories/Caliper_Rebuild.pdf

 

That is a good article. So how do I tell if I have stuck caliper. What should I look for.

 

Calipers stuck in TWO ways:

The caliper slides on two pins. Those pins can get rusted/seized and the caliper will not be able to center its self on the rotor. MAKE SURE that the sliding pins are free to move and you use the correct synthetic grease to grease them.

The pistons can get stuck in the bores. Open the bleeder screw. Use a screw driver to apply force on the brake pad and force the pistons back into the caliper. Close the bleeder and apply the breaks several times and the pistons will push the brake pad back out to the rotors. Make sure that you keep the fluid level up in the master cyl.

BC

 

So do you clean the pins with a scotchguard pad or fine sandpaper, or do you replace the pins with new ones. What is the correct synthetic grease. Thanks again for the info Bill. I appreciate all the help.
Chuck B