Tutorial: EBCM model V C1214 code fix on a 1999 with AH
My '99 started throwing the C1214 code around 98,500 miles, at first it would throw the code after I hit a bump or drove over some rough pavement, I would clear it, it would go away for a while, then I'd hit another bump and it would come back. It started getting more frequent and would sometimes just come on out of the blue. To me this pointed to an intermittent connection somewhere, either due to corrosion or a bad solder joint.
My first course of action was to check/disassemble/clean all of the grounds, plugs and fuses involved in the EBCM system. This did not resolve the problem. Seeing as no one serviced pre 2001 EBCM modules and I didn't have $1,000-2,000+ for a used one, I decided to try to fix it myself as I had nothing left to loose.
You need to be really good at de-soldeing if you want to attempt this. I believe the reason no-one services the pre-2001 units is because de-soldering the circuit board holding the relays and de-soldering the relays themselves is an immensely aggravating and delicate task. I will include some tips and tricks in the notes below.
Part one: EBCM removal
Tools needed: T25, T30, 10mm socket, various extensions and universal joints.
1) remove the air bridge and TB coupler
2) unplug the main connector by lifting the latch up and pulling it out
3) unplug the BPMV ground connector (single wire)
4) loosen the 2 10mm nuts attaching the BPMV (drivers side) to the bracket.
6) remove the stud and grommet for the 10mm nut. The stud for the 10mm nut sits on a rubber grommet that sits on a T30 bolt going through the EBCM to the BPMV.
b) pull off the stud and cap
c) pull off the rubber grommet
8) remove the 4 T25 bolts in each corner of the EBCM
9) detach the EBCM from the BPMV and remove it.
Part two: EBCM relay replacement
Tools needed: T15, soldering iron (30W), solder sucker, de-soldering braid, flux-core solder, non-metallic prying tools. Patience, sooo muuuch patience.
1) remove the 2 T15 bolts holding the circuit board to the case
2) de-solder the 6 large connections in the upper-right hand corner
3) de-solder the 9 small connections in between the 2 relays
b) take care not to burn the large electrolytic capacitor, it is extremely sensitive to heat.
5) de-solder the relays
6) solder in new relays
7) re-solder the circuit board connections
8) re-install the ECBM
Notes:
For EBCM removal, removing the upper radiator hose will help with access, but isn't necessary, I didn't.
De-soldering tips:
1) Do not use too hot of an iron, as it will burn the solder leads off the PCB. I had my iron set to 30w the whole time.
2) if the old solder isn't melting well, add some fresh flux-core solder to it, it should then melt easily.
3) if you can't get all the solder out of a connection, and only a little bit remains, melt it, and jiggle the pin around in the hole with a pair of plyers while the solder cools to keep it from sticking to the pin
4) for any connections where the previous 2 tips didn't help: use a plastic/nylon to pry up on the PCB from one side and melt the remaining connections in order to gradually lift the PCB off of them
5) you can wedge a plastic/nylon tool between the relays and the PCB and take turn melting the pins and wedging the relay apart from the PCB.
I replaced both of my relays since I didn't want to have to do this again if the other one went bad and the cost of a second relay is negligible.
Notes on replacement relays:
You will not find exact Bosch replacement replays, but any relay that meets the following criteria will do:
Single Pole Single Throw
4 Pin (no 87a)
50 Amp
Normally Open
No resistor in parallel with the coil
Footprint must be the same
I suggest you source a suitable replacement before hand. Here's where you have wiggle room:
1) If the relay has a mounting tab on the case, you can cut it off
2) If the relay is a socket type, you can cut the pins shorter so they wont extend too far past the PCB (about 1/2 their length)
3) the fuse for the system is 40amps, so you can probably get away with a 40amp relay instead of a 50amp.
4) if you can only find a 5 pin relay, you can cut pin 87a off.
So there you have it, a days work and $15 for two new relays, and my Vette is happy again. Godspeed to the rest of you dealing with this issue.
Last edited by Robert Perkins; Dec 30, 2015 at 03:17 PM. Reason: Left off comments
I took some photos but they don't show anything not already seen in Chuck Cow's post...
Prior to your repair was your ABS and traction control lights on? Have you driven it and and forced the ABS and active handling to activate? Results?
My '99 started throwing the C1214 code around 98,500 miles, at first it would throw the code after I hit a bump or drove over some rough pavement, I would clear it, it would go away for a while, then I'd hit another bump and it would come back. It started getting more frequent and would sometimes just come on out of the blue. To me this pointed to an intermittent connection somewhere, either due to corrosion or a bad solder joint.
******************
Part two: EBCM relay replacement
Tools needed: T15, soldering iron (30W), solder sucker, de-soldering braid, flux-core solder, non-metallic prying tools. Patience, sooo muuuch patience.
I suggest you source a suitable replacement before hand. Here's where you have wiggle room:
1) If the relay has a mounting tab on the case, you can cut it off
2) If the relay is a socket type, you can cut the pins shorter so they wont extend too far past the PCB (about 1/2 their length)
3) the fuse for the system is 40amps, so you can probably get away with a 40amp relay instead of a 50amp.
4) if you can only find a 5 pin relay, you can cut pin 87a off.
So there you have it, a days work and $15 for two new relays, and my Vette is happy again. Godspeed to the rest of you dealing with this issue.
Most appreciated! Good job and likely a bit neater than MY desoldering stuff. BRAVO!
Not a job most people would want to tackle cause the desoldering is a PAIN IN THE *** and messy.
If you're accustomed to doing such work and are confident, then this is a good approach to try.
It will not fix EVERY ABS LIGHT, but some of the RELAY RELATED codes will usually fix this way.
Given there is NO CHANCE of a replacement unit coming around any time soon, this is a great way to
fix them and make the car whole again.
NOW, hopefully you start getting some of the million calls I get every week about this repair!!!

GREAT JOB and nice write up!
Chuck CoW
Last edited by Chuck CoW; Jan 4, 2016 at 10:03 PM.
DO PROPER DIAGNOSTICS FIRST and eliminate all the other EASY fixes first....
Then go at the module.... It's not fun...
Chuck CoW
Prior to your repair was your ABS and traction control lights on? Have you driven it and and forced the ABS and active handling to activate? Results?
You should make sure your code is C1214, as there are other reasons those lights and messages may appear.
I have triggered my ABS and Traction Control several times since the repair and they worked perfectly without throwing a code.
Please check the grounds, connectors, and fuses in the system first as this really is a last resort fix.
The Best of Corvette for Corvette Enthusiasts
Last edited by Pvt_Murphy; Jan 20, 2016 at 11:29 AM. Reason: Inaccurate statement, replay solder joints not visible until PCB removed.
http://www.mouser.com/ProductDetail/...ty/7-1393302-7
http://www.mouser.com/ProductDetail/...ty/7-1393302-5
The 7-1393302-5 relay is a plug type, so you'll need to trim the pins.
Last edited by Pvt_Murphy; Jan 20, 2016 at 11:29 AM. Reason: typo
https://www.autoecu.com/electronic-c...-bpmv-new-1pc/
Good luck to any that attempt this repair.
Also If you are in the same boat as I am with a completely missing trace due to the capacitor blowing up from the bottom and catching fire, here's a link to a Nichicon capacitor that should work
https://www.ebay.com/itm/202909875730
The model number is different being H9508 instead of H9738 but should work perfectly. All other specs match up.
50 amps and made for ABS control among other things, but I'm wondering if the two larger blades will fit through the slots on the board without modification.
Thanks!
~jay
Looking at the blades for the relays in this picture, (don't mind the black lines, I was drawing a clearer line for one of the traces I had to jump/replace) they do not offer very much wiggle room. I personally would try to go with the OEM relay or ones that fit as modifying electrical systems to work can be completely fine, I would do OEM just for the ease of replacement. It took me about three hours to disassemble my module, replace both relays, replace my blown capacitor, and solder in three jumper wires. It's not very hard, but I would recommend a solder sucker, a good soldering iron, and flux. With patience and enough time, the job should come out clean and fairly simple. Wear a face mask of some sort as well due to the fumes from solder. I would hate to recommend this process to someone without warning them of this as well due to the fumes being able to cause cancer and other various health issues.
I believe I covered everything I could think of. In short, I would personally recommend the OEM relay for ease. I still do believe the others could be made to work but it would probably take much longer to do. The OEM ones as well are a little cheaper too which is nice. If I were going to do this repair again as well, I would buy two or three as well just in case this happens again in the future. There's no telling how long these relays will be available due to how the market is and its always nice to have a little security.
I hope I could help you out and that your repair goes well.
No in-stock indication, so hopefully the order is successful.
~jay
The question is, should I replace the relays as well.... I know I should but I don't want to mess with too much.... Encouragement or advice sought. Thanks
The question is, should I replace the relays as well.... I know I should but I don't want to mess with too much.... Encouragement or advice sought. Thanks
Thanks again for responding, these forums keep the C5 alive. I've only had myne for a few weeks and I knew what I bought, although I thought the 01-04 mod would suit my 99 as well... Not to worry, the worst I can do is not fix the issue 😁 It's always good to try.
QUOTE=Gabe Graham;1606594725]In my case where I wasn’t sure whether or not my relays actually did work, I still replaced them. I had no way of knowing what was actually working vs non working. For peace of mind, I would personally replace them. It’s a bit of a process if you’re not familiar with soldering but well worth the effort if they decide to go out a week after replacing the capacitor. Best of luck though with fixing it![/QUOTE]










