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Hello to all I have a 2003 zo6 and have the ebcm abs trac module removed. I replaced the relay with the one in the photo. Still not working. the number on the relay are not the same but is supposed to be a replacement. The drive motor will cycle ok and all fusses check out ok. My question is their a way to power up the key and check voltage and or resistance at the pigtail and what I should read. To me it looks like it has been repaired before I became the owner.
Last edited by sideshow bob; 06-18-2018 at 06:10 PM.
Reason: more
LOL months back I get on a Corvette forum NOT this one and list my trouble codes only to be told that's what the search button is for buddy by several members. And given no help. So that's what I did. I searched every forum on the internet I watched all the the YouTube videos with my trouble codes. That's what got me to this relay I've checked every ground did the solder joint check looked up found a place that claims it's a replaceable relay with the part number shown in my photo. I was hoping that my photos would show that I must have done my homework, and that it got me this far. Sincerely yours just can't win
Lionel makes a good point though.. if you give the codes it would help narrow down the solution. I've had to resolder the 5 posts on that board twice now. I don't know if I didn't get them good enough the first time 5 years ago but I recently had to redo them and it has cleared up my issues with the EBCM again. It looks to me like those 5 posts need a better solder job on them. Again, I'm not expert just my opinion based off your picture.
Thanks
C1241H
C1248H
C1255H
C1288H
You are correct the photo is of the module before I removed the relay. Which is what made me believe it had been worked on before.
Yeah the dreaded 1255 I gave you codes from a list I had made before the repairs. When I started the car and the warning lights did not go away. I did not rechecked what the new codes were. Sorry frustration was building. I have had this module on and off so many times I can do it blindfold. New code is just one C1218 witch I know is bad grounding. I have checked and cleaned all the spots. Even opened up the two small ground boxes on front fenders passenger and Driver side. So it looks like I'm making some progress. I don't get those little boxes for grounding seems like you could just splice all those ground wires together. So I'm going check all grounding points. Thanks
Circuit Description
The system relay is energized when the ignition is ON. The system relay supplies voltage to the solenoid valves and the pump motor. This voltage is referred to as the system voltage. The electronic brake control module (EBCM) controls each solenoid valve by grounding the solenoid. The EBCM controls the pump motor by grounding the control circuit. The pump serves 2 purposes:
�� Transfers brake fluid from the brake calipers to the master cylinder reservoir during pressure decrease events.
�� Transfers brake fluid from the master cylinder reservoir to the brake calipers during pressure increase events.
Conditions for Running the DTC
�� The pump motor is commanded ON.
�� The system voltage is greater than 8 volts.
Conditions for Setting the DTC
One of the following conditions exists for 0.16 seconds:
�� With the commanded pump motor voltage less than the system voltage, the actual pump motor voltage is 3 volts less than the commanded voltage.
�� With the commanded pump motor voltage greater than the system voltage, the actual pump motor voltage is less than 8 volts.
I'd check the pump voltage when it's cycled on during the start. It's possible you have a gummed up pump that needs to be operated and have fresh fluid flushed into it.
Thanks I had just printed out the DTC C1218 manual and was looking to see the best way to cycle the pump. I've put 12v to the motor for a second or two just to make sure it would turn. Don't want to burn up a motor without knowing a good procedure. learned on a different car not get air in the EBCM manifold in less you have a scan tool to cycle the pump and open up checks in the manifold. Funny thing to get the C1218 after the relay change.
That was with the module off the valve body. I will try it again hooked up to the motor. Just wanted to see if I had power out of the module. I have cycle the motor with 12 volt battery power and it sounded like it spins freely. Do you think it would hurt the motor to power it up for more then a few seconds.
Last edited by sideshow bob; 06-21-2018 at 01:36 PM.
Reason: wrong word
Your only hope is the problem is due to power or ground issues. If the module has a good ground and a good source of +12V power the C1255 means the module is shot. None of the codes you posted have anything to do with the relay.
Check the ground for the EBCM electronics which is located on the frame below battery. The BPMV ground is near the module. Make sure your battery connections are clean and tight and the battery ground cable has a solid connection.
C1255 is a non repairable failure requiring replacement of the EBCM.
Thanks Bill
When I started this repair I had read that it may have a slim chance to clear the c1255
At $11.00 dollars for two relays with shipping I thought it was worth a shot. I have cleaned that ground spot and all others using a diagram printed off the internet. All seems good with grounding. Not sure if you see in my post that I'm just getting a c1218 code only now.
06-18-2018, 06:04 PM
The dreaded EBCM
