EBCM Issues
Thread Starter
Racer
Joined: Aug 2022
Posts: 274
Likes: 185
EBCM Issues
I have a 1997 C5 Corvette with the "M" module EBCM. I have been having issues with my ABS and traction control lights coming on. The light usually comes on while accelerating hard or hitting a bump in the road. The lights always go away when the car is turned off and restarted. Then it will be good for a while then come on all the sudden after hitting a pothole or something.
Here are the historical codes I am getting:
BCM: b0503 b0508 b2592 b2721 b2723 u1040
TCM: c1225 c1226 c1255
I have had some battery issues with the car dying easily, so I plan on replacing that, I am not sure if that may be a potential cause. Does anybody know what could be causing this issue? Should I try unplugging and replugging in the EBCM? Hopefully it doesn't require a replacement as pre 2001 EBCM units are almost impossible to get
.
Here are the historical codes I am getting:
BCM: b0503 b0508 b2592 b2721 b2723 u1040
TCM: c1225 c1226 c1255
I have had some battery issues with the car dying easily, so I plan on replacing that, I am not sure if that may be a potential cause. Does anybody know what could be causing this issue? Should I try unplugging and replugging in the EBCM? Hopefully it doesn't require a replacement as pre 2001 EBCM units are almost impossible to get
.
Melting Slicks
Joined: Sep 2021
Posts: 2,555
Likes: 1,213
The good news is you can still drive the car even if it fails. You won't have ABS or traction control but you won't be stranded.
The other good news is the car thinks the pump is working because it's passing the start-up test. If it didn't, the light would come on (or never go out) right after starting the car.
Looking in my 2000 service manual:
C1225 & C1226 indicates a LF and RF excessive wheel speed variation.
The bad news- C1255 is internal EBTCM malfunction. The manual (page 5-171 in my 2000 manual) says when DTC C1255xx is displayed on the scan tool it will be followed by two additional numbers to help determine the malfunction.
I can post screen shots of the relevant pages from the manual.
The other good news is the car thinks the pump is working because it's passing the start-up test. If it didn't, the light would come on (or never go out) right after starting the car.
Looking in my 2000 service manual:
C1225 & C1226 indicates a LF and RF excessive wheel speed variation.
The bad news- C1255 is internal EBTCM malfunction. The manual (page 5-171 in my 2000 manual) says when DTC C1255xx is displayed on the scan tool it will be followed by two additional numbers to help determine the malfunction.
I can post screen shots of the relevant pages from the manual.
Melting Slicks
Joined: Oct 2007
Posts: 2,375
Likes: 426
Replace your battery. These cars hate weak batteries. Then clear all your codes. Start clean with your new strong battery.
The Left Front and Right Front wheel speed variations can be caused by bad connections in the wiring from the hubs to the EBCM. There is a connector a few inches from the hub, then 2 more connectors on a 2 foot jumper wire to the front wiring harness. It's usually these connectors that need work. They have male and female sides and they can be taken completely apart, cleaned and re-assembled. You can sometimes cheat by swapping the jumper wires from left to right - side to side. You might get a year or two then swap them side to side again. Eventually you may have to buy a new jumper wire.
Can't help you with the C1255. But I'll say this: clean your grounds. All of them.
The Left Front and Right Front wheel speed variations can be caused by bad connections in the wiring from the hubs to the EBCM. There is a connector a few inches from the hub, then 2 more connectors on a 2 foot jumper wire to the front wiring harness. It's usually these connectors that need work. They have male and female sides and they can be taken completely apart, cleaned and re-assembled. You can sometimes cheat by swapping the jumper wires from left to right - side to side. You might get a year or two then swap them side to side again. Eventually you may have to buy a new jumper wire.
Can't help you with the C1255. But I'll say this: clean your grounds. All of them.
