Allied Electronics? thanks, so it's the same part number?

me also... part number? URL ? :thumbs:

c'mon man don't bogart all the relays bro! :D

relay (from earlier entry this thread)

http://octopart.com/t7ns5d1-12-amp-863636

:thumbs:

Please Note: The relay PB380-ND HAS BEEN SUPERCEDED BY PB1321-ND

Marked :)

Very Very good post!:rock::woohoo:

Thank you very much jrhott, I updated the info with the PN you provided.

Does this apply if I have the C1255 code?

1255 is usually a BAD indication. Something inside the EBTCM microprocessor isnt functioning correctly.

You can try all the recommended solder repairs but, it may not work.

Document ID# 670687
2001 Chevrolet/Geo Corvette


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DTC C1255 or C1256
Circuit Description
This DTC identifies a malfunction within the electronic brake control module (EBCM).

Conditions for Running the DTC
The ABS conditions and the braking conditions are normal.

Conditions for Setting the DTC
An internal EBCM malfunction exists.

Action Taken When the DTC Sets
C1255
If equipped, the following actions occur:

The EBCM disables the DRP/ABS/TCS/VSES for the duration of the ignition cycle.
The ABS indicator turns ON.
The Traction Control and Active Handling indicator turns ON.
The red Brake warning indicator turns ON.
The DIC displays the following messages:
Service ABS
Service Traction System
Service Active Handling
The EBCM will also set DTC C1248.
For some DTC C1255xx, the EBCM disables the variable effort steering (VES) for the duration of the ignition cycle.
C1256
The ABS remains functional.
The ABS indicator remains OFF.
Conditions for Clearing the DTC
The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
Diagnostic Aids
The scan tool displays 2 additional characters after the DTC. Take note of the 2 character code and any other DTCs that are set. The 2 character code is an engineering aid used in order to determine the cause of the internal malfunction.
When the scan tool displays DTC C1255m3, the EBCM has not been programmed. Perform the setup procedure for the EBCM.
Test Description
The number below refers to the step number on the diagnostic table.

Determines whether the DTC is current.

Step
Action
Yes
No

Schematic Reference: ABS Schematics

1
Did you perform the ABS Diagnostic System Check?
Go to Step 2
Go to Diagnostic System Check - ABS

2
Install a scan tool.
Turn ON the ignition, with the engine OFF.
Use the scan tool in order to clear the DTCs.
With the scan tool, perform the Automated Test.
Does the DTC reset as a current DTC?
Go to Step 3
Go to Testing for Intermittent and Poor Connections in Wiring Systems

3
Replace the EBCM. Refer to Electronic Brake Control Module (EBCM) Replacement .

Did you complete the repair?
Go to Step 4
--

4
Use the scan tool in order to clear the DTCs.
With the scan tool, perform the Automated Test.
Does the DTC reset?
Go to Step 2
System OK



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Document ID# 670687
2001 Chevrolet/Geo Corvette

Geo Corvette??? That's demeaning...

Thanks for the info Bill. What I find strange about my particular case is that this will occasionally "fix" itself from time to time. The only problem is that, while it's "fixed", the active handling is actively trying to kill me by applying brake pressure at the most random times during normal driving. The only way to remedy it is by disabling the TCS. I found a vendor on fleabay that swaps your EBCM for theirs so I guess that's my only option at the moment. I keep missing the very rare "EBCM for $200" posts on the parts for sale forum.

A few more tips about the repair
 

Was ready to send mine out to ABS fixer when I saw this sticky. I've done a fair amount of automotive repair work, so figured I could knock this one out in an hour or two. Here are a few tips based on my 4 hour job...

• Removing the EBCM took me nearly 90 minutes. Access to the middle torx screw at the front of the car is blocked by the line running to the radiator on my car. Had to put far more pressure on that to wedge it out of the way to remove the screw than I would have liked. I was able to push this line toward the engine far enough to get my torn driver in there. Just be careful not to over stress this line!

• GM says to gently pull the EBCM from the brake module. Ha! I started with a small screwdriver as the post suggested in the 3 spots indicated. Couldn't get it to budge. Eventually used two bigger screwdrivers at the same time. You have to be careful not to damage the rubber gasket in the middle, but once I got it off, I realized I could have pried deeper on the two corners because the gasket runs below the screw holes. You have to do more than break the seal loose; no amount of pulling by hand would separate these even after I used the screwdrivers to gently pry to break the seal. You need to spread them apart about a screwdriver width before you can pull them apart by hand. I wasted a lot of time pulling and pushing once I thought I had broken the seal when I hadn't.
  • I have three center punches. None was long enough to reach the cover through the small hole. The hole on mine is tapered so a much smaller diameter punch or screw must be used than I realized. I used a small steel rod and a hammer along with a heat gun to get a tiny bit of movement on the lid. Then I reheated and used screwdrivers to slowly pry. Heated it 5 times. The aluminum case is really soft and I got a few nicks from prying. Four screwdrivers around the perimeter finally released the cover. Extra silicone for those spots upon reassembly.
  • Even with a small magnifying glass, I couldn't tell for sure which contacts might have been cracked. They are very small! I soldered all 5 to be safe. This part took about 5 minutes. My eyes are getting worse in my 40 s but wow those are small.
  Reassembly was relatively easy. All codes are cleared. Thanks to the forum once again!

I did this fix today. Reset all codes and drove it, so far so good. Thanks for the info!

Fantastic post,,,,fixed my 01 vert in under 2 hours

Hi guys ! I've tried to fix mine, I've changed relay (found on digikey.com) remount ebcm, and then I have a new code 58-SDM U1040 and 'Service Column Lock' message (my steering wheel is blocked too)

when I remove ebcm and turn the key the message 'Service Column Lock' don't come back and I can move my steering Wheel

Here is the relay I've received (I ordered PB1321-ND and this is what invoice mentioned)
http://i35.servimg.com/u/f35/16/88/84/68/img_2012.jpg

Does anyone know how to do please ?

I have ordered relays before. Be sure to check the normally open contacts are OPEN and not close. It is possible to have a look alike that is opposite to what you need.

None of those new DTCs are related to anything that you did to the EBTCM.

Make sure that your battery is fully charged and it is a good idea to have it full tested at a parts store or service center.

Make sure that the battery has proper reserve capacity and its able to hold voltage under load. If the battery us good, reinstall and make sure that the terminals are properly torqued tight ( 11 ft/lbs for 97-2003 C5s )
Once the battery is fully tested , fully charged and reconnected, pull up the DTCs and clear ALL the DTCs. When you reconnect the battery, it will set random DTCs and all should be set as HISTORY or "H" codes.

You need to purchase and install a COLUMN LOCK BYPASS module. The best one to purchase is the LMC-5. It will eliminate the locked steering wheel problem and the 2 mile per hour fuel shut off.

READING YOUR Engine Diagnostic Codes (DTCs)
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 etc…)
3) Press and hold OPTIONS
4) While holding OPTIONS, press FUEL four times within a 10-second period.

Initially, on-board diagnostics go into an Automatic Mode which 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. ( 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 kinds 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.
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.

Here is very good site of DTC definitions:


http://www.gearchatter.com


Make sure to include the H or C suffix!!

I remember now, few days ago I have "Pull Key, Wait 10 Seconds" message and engine shut down, but column lock only when I remount ebcm module I will buy LMC5 module on eBay, see what happens, and come back here, thank you.