Replaced my relay and I am now good to go!!!

:iagree:

Good to hear and thanks to all who followed this. Wouldn't be a good write up if no one did the repair.

I have a 98 that just started to throw these same codes intermittently , others have reported. I pulled mine out today, is there still not a fix for these years?

Half that can be removed from the car.
http://i46.tinypic.com/1z1tmdl.jpg
http://i46.tinypic.com/bfkrpw.jpg

The other half still attached in the car.
http://i50.tinypic.com/2qi9t1k.jpg

Code 1274
 

Well I have an 01 c5 with 50k miles always garaged never in rain. I live in california., I would get the 1214 code and abs, Traction control message when I would start the car, If I started it a second time the message would go away. It would not happen every time. So I found this thread and removed the EBCM and found a couple of solder joints bad, I resoldered the bad connections, When I installed it for a test the 1214 was gone but the code 1274 came up with the abs, traction control message, I can't clear the 1274, and the message is on constant. I have checked and cleaned the grounds, and checked the elect. connections.
What did I do wrong ?

Here is the DTC write up. Looks like you have to disassemble the unit and do a closer circuit board inspection.

Document ID# 670689
2001 Chevrolet/Geo Corvette


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DTC C1261-C1274
Circuit Description
The system relay is energized when the ignition is ON. The system relay supplies voltage to the valve solenoids and the pump motor. This voltage is referred to as the system voltage. The electronic brake control module (EBCM) microprocessor activates the valve solenoids by grounding the control circuit.

Conditions for Running the DTC
The system voltage is greater than 8 volts.
The ignition voltage is greater than 9 volts.
Conditions for Setting the DTC
The commanded state of the driver and the actual state of the control circuit do not match for 0.03 seconds.

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

The EBCM disables the ABS/TCS/VSES for the duration of the ignition cycle.
The DRP does not function optimally.
The ABS indicator turns ON.
The Traction Control and Active Handling indicator turns ON.
The DIC displays the following messages:
Service ABS
Service Traction System
Service Active Handling
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 solenoid valve circuit is internal to the EBCM. The solenoid valve circuit is not diagnosable external to the EBCM. The DTC sets when there is a malfunction in the solenoid circuit internal to 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# 670689
2001 Chevrolet/Geo Corvette

Ebcm
 

Well I pulled the EBCM and looked again, All soder connections look good, I took an ohm meter and checked the power and grounds from the terminals to the board and they checked good, In reading this thread the relay may need to be replaced, does anyone have a sceamatic for the relay so I can check to see if there is an open or a solid connection that should not be there, also I don't have a scan tool. I pulled the codes from the dash.
Thanks,

I use a silver solder (62%-tin, 36%-lead, 2%-Silver) which is stronger than regular solder.

I haven't had to fix the EBCM yet, but I have fixed the HVAC display. Silver solder melts at a higher temp but makes a beautiful solder joint.

I got the solder at Radio Shack but it would be cheaper at digikey.com or mouser.com.

Good luck on the repair.

OK, I checked all solder joints and no pin damage, it still has the code 1274 and will not clear, I guess the next step would be to replace the relay. or replace the EBCM.

Before you make your move,,, get a meter and check the relay contact resistance. Heres a post for you to check out . It shows you what a bad relay contact looks like.. Look at post 77 to the end:

http://forums.corvetteforum.com/c5-t...post1581990753

Note sometimes the resistance of the relay goes up and can't be measured properly. The pin that holds the high current contactor is normally a rivet and the heating/cooling causes the rivet to change resistance and the problem may be in the rivet not the contacts themselves. My advice would to replace the relay anyway.

Just to clarify, only 97-00 cars with active handling have an ebcm, correct?

Thanks for the help, I measured the resistance with the relay installed,
between a1 and a2 = 175.6 ohms
between 11 and 12 = .2 ohms
between 11 and 14 = 2.64
I am not sure what the values should be .

Thanks.

No. All years have an EBCM.

No all years have them, but the 97 - 01 cars use a different part and so far no solution has been found to repair them and GM doesn't support the car by having this part available.

Not quite Jim....2001+ are indeed repairable(within reason).

Preface by stating my parts manual only goes up to 2002......

97-98(early) are the same....and are rear mounted.

98(late)-2000 are the same - front mounted

2001 and 2002 are different part numbers - front mounted

This was posted a few days ago regarding a fix for the '97 & up ones.
http://forums.corvetteforum.com/c5-g...abs-units.html

COOL didn't have that data. Thanks for the info. I have a 99.

I pulled the relay out, took it apart and put 12v to it and it worked. the points looked good, so maybe I have a different problem. the relay I have is a T72M5D155-12-12. is the
T7NS5d1-12 the same?
Thanks

Try removing all fuses related to the ebcm all at once....clean the leads real well and put them back in.