Originally Posted by 87SAM

Looks like this is the same issue you had back in January with all the codes (nearly identical post). Clear all the codes and see what comes back as this will help narrow it down a bit.

Originally Posted by Jack Daniels

Indeed it is 87SAM - just now getting around to addressing it. How do I clear the codes?

Thanks.

Originally Posted by Bill Curlee

POST DTCS!!!

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!!

Originally Posted by Chicago1

Absfixer.com should be able to fix it for 150 or so. Or you could do it yourself for much cheaper. SO a search and you should see a few how to's.

Originally Posted by Chicago1

Absfixer.com should be able to fix it for 150 or so. Or you could do it yourself for much cheaper. SO a search and you should see a few how to's.

Originally Posted by cdkcorvette7

if your car is an 01 or later... Removing the module is easy; there are instructions on absfixer.com

Originally Posted by Jack Daniels

Haha, OK guys, reset the codes earlier today and here are the codes I got from driving today - just checked them:


10 PCM

P1431


28 TCS

1248H
1255H
1267H
1283H
1287H


So how bad is it? I see the C1255 again, which 87SAM called the kiss of death. LOL. I gotta be honest here, I'm scared fellas. Am I driving a ticking timebomb?

Originally Posted by seoulbrooks

Thought this might help you out. As you can see from the subcodes some C1255 faults are due to a ground or voltage disruption. Use the wiring schematic and make sure all input voltages are good and check and clean every ground. I cut off the C5 ground plugs and soldered on ground lugs for each one. I also noticed on alot of the grounds the crimp is around the actual insulation of the wire and some of the pins in the ground plugs are not zero resistance to ground. I also removed the EBTCM plug and cleaned an resprung all pins to insure good connections. Also made a new ground point for the EBTCM and BPMV so they would not be effected by other sources. Make sure ALL grounds are clean and tight. I have not had a TC/AH fault since......before I was getting them on every daily drive.........

I did all of my repairs due to Bill's advise on many threads......

Along with the C1255, a 2 digit Sub Code will set. The first digit is a Letter, and the 2nd digit is a number. Note that only the Tech 2 will display these sub codes, using the On Board Diagnostics through the Drivers Information Center on Cadillac and Corvette WILL NOT display sub codes.

Here is a list of the Sub Codes that may set:

E0, E1, E2, E3, E4, E5, E6, E7 M0, M1, M2, M3, M4, M5, M6, M7

Probable Cause: Each sub code represents a specific malfunction. Most sub codes set due to a malfunction internal to the EBTCM, and can be repaired by replacing the EBTCM. However, EBTCM replacement is NOT always necessary when DTC C1255 is set. Here is a list of exceptions where a fault external to the EBTCM will set C1255.

C1255 E2: This Sub Code may set due to a loss of battery or ground to the EBTCM.

Battery Cable disconnect
EBTCM Fuse Pull
EBTCM harness disconnect
Weak or Discharged battery
Any other interruption of battery or ground to the EBTCM
C1255 E2: Can also set when an EBTCM is first installed on a vehicle. C1255 E2 will be stored as a history code only, and WILL NOT turn on the ABS light. A typical service scenario is when an EBTCM is replaced for a DTC other than C1255. The vehicle again returns with the ABS light on, and C1255 E2 is set as a history DTC along with the original DTC which brought the vehicle in for service. The servicing technician is erroneously convinced that the new EBTCM is defective.

Replace the EBTCM for C1255 E2 only when a source of a battery disconnect cannot be identified and was not set due to EBTCM replacement.

C1255 M5: This Sub Code indicates that the EBTCM has detected a malfunction in the one of the Wheel Speed Sensor Circuits, and sets along with Wheel Speed Sensor DTCs (C1221 thru C1235). Disregard C1255 M5 and perform diagnostics for the other wheel speed DTCs. Only replace the EBTCM if all other wheel speed sensor diagnostics have been exhausted and the source of the DTCs cannot be identified.

C1255 E4 and E6 set together: This sub code combination sets when the pump motor ground circuit has detected B+. This condition can occur if the BPMV ground circuit is shared with other components and the ground bolt is loose or disconnected. These other components are seeking ground, then back-feed into the EBTCM thru the BPMV.

Sorry so long but thought it might help out some 2K owners.....

Originally Posted by Jack Daniels

Chicago1, yes, the reset cleared the codes right away.

Vette is 2002 Z06.

Dropped it off at England Green today to look at this and other issues.

Thanks a ton guys.

Originally Posted by 87SAM

I don't know about that. Look at all those C codes, which includes the C1255 which can be the kiss of death unless it lost power or has a bad ground or something.