I think I have read through almost every post on the C1255 code for early models.Spent most of 2 days just reading,and still can't believe there is not a definitive way to fix these modules.It seems some have gotten lucky,others fixed a relay,some fixed their grounds,others found used parts,dealers screwed many.

I have called BBA manufacturing and Auto Ecu.Although,AutoEcu said yesterday they thought they could fix this code.He was supposed to call me back later in the day.This code is a PIA.One member here is having a problem with BBA right now,it seems he cannot get his ABS unit back!

Just complaining here.I have lived with the code C1255 for about 2 yrs.Just didnt have the time to spend on it. I have been through the grounds with some help from a friend and his multimeter.I am not an expert with that!

I read through,but not always understood what Bill Curlee is talking about!Wow,Thanks Bill!

Ok,done complaining.Thanks to ALL members that have posted or have been through this problem.I am learning a ton,but still no fix for me.I will call AutoEcu again on Mon.

I may just take this thing apart myself! I have soldered capacitors before into my 89 vert front speakers that worked great when I finished.Sooooo,time will tell.

Matt

 

I've seen this code after connecting up to a software system to adjust things in the PCM. Also seen this after the dealer hooks up a Tech2. I've always just cleared it and it does not come back till the next time something interfaces with the PCM

 

Coincidence maybe,this code did show up around the time I had a guy adjust the Pcm a little..but who knows?
thanks,Matt

 

DO THIS!

1. Charge the battery. Make sure that it is in good condition. Take the car to AutoZone, Advance or anywhere that will FULLY test the battery and make sure its in good shape.

2. Clear ALL the DTCs using the DIC:

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.

NOTE and a WARNING. You can read the DTCs while the engine is running. I pull mine up all the time while driving.
WARNING. Don’t become distracted while reading DTCs while your driving and cause an accident!!!!! Use common sense and drive safe.

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!!
---------------------------------------------------------------------

Make sure that the module is getting proper POWER & GROUND. Physically examine the power and grounds to that module.



If all else fails

DTC C1255 EBTCM Internal Malfunction




Circuit Description
This DTC identifies a malfunction within the EBTCM.

Conditions for Setting the DTC
DTC C1255xx is set when an internal EBTCM malfunction exists.

Action Taken When the DTC Sets
ABS/TCS/Active Handling (if equipped with RPO JL4) are disabled.

Indicators that turn on:
ABS indicator
Car Icon (TCS indicator)
Messages displayed on the DIC:
Service ABS
Service Traction System
Service Active HNDLG (if equipped with Active Handling RPO JL4)
Conditions for Clearing the DTC
Condition for DTC is no longer present and scan tool clear DTC function is used.
Fifty ignition cycles have passed with no DTCs detected.
Diagnostic Aids
When DTC C1255xx is displayed on the Scan Tool, it will be followed by two more numbers which should be noted along with any other DTCs that may be displayed. The additional two numbers displayed with DTC C1255xx are for aiding engineering to determine the cause of the internal malfunction.
Make sure the integrity of the connection between the EBTCM and the BPMV is secure, tight, and free from corrosion.
DTC C1255xx EBTCM Internal Malfunction (ABS/TCS Disabled) Step
Action
Value(s)
Yes
No

1
Was the Diagnostic System Check performed?
--
Go to Step 2
Go to Diagnostic System Check

2
Are any other DTC(s) present besides C1255xx?
--
Go to Applicable DTC Table. Refer to Diagnostic Trouble Code (DTC) List
Go to Step 3

3
Turn the ignition switch to the OFF position.
Disconnect the EBTCM.
Check for damaged, pushed out, or miswired terminals.
Was any damage found?
--
Go to Step 4
Go to Step 5

4
Repair as necessary.

Is the repair complete?
--
Go to Diagnostic System Check
--

5
Replace the EBTCM. Refer to Electronic Brake Control Module (EBCM) Replacement .

Is the replacement complete?
--
Go to Diagnostic System Check
--



--------------------------------------------------------------------------------
Document ID# 220977
1998 Chevrolet/Geo Corvette

 

I have been pulling codes for awhile now....I will get to AZ asap.Battery is less than 2 yrs.old. But,I had the code with OLD battery as well.i have reset others codes in the past.This is the ONLY code I have.

ABS light is on,as is TCS on dash...all other modules are good ...for now.

I added a ground from the head to the frame today,,as per the Forum..The Big 3..

I have gone through grounds as well with a friend using his Multimeter checking grounds for resistance.Nothing wrong that we have found YET!!.......sigh

Still putting the battery and fender back on from the Vacuum leak i had with the bad check valve and line replacement.

I have been a Bill Curlee follower for quite some time!!!LOL

My kids kept me from getting it all done today.....will post soon

Thanks,Bill!!!!

 

The only code I have IS THE..........C1255HC

Forgot to add that!

Thanks again Bill!!