Jenn's Seville lit up like a Christmas tree right around Christmas. There were many codes for various reasons, but the reason the brake, ABS, and traction control lights were on boiled down to these two codes:
Sounds serious. Relevant pages from the FSM:
These steps are essentially:
- Unplug things
- Test resistances
- Fix wires or replace EBCM (Electronic Brake Control Module), the thing that runs the ABS hydraulic pump.
The wiring is fine. Conveniently, I had been watching videos about C5 Corvette common failures and the EBCM is one of them. It appears that a relay becomes un-soldered form the PCB internally which initially causes intermittent system test failures, then permanent failures. Conveniently, GM stopped making these parts. You can fix it, though. Once disassembled, you can re-flow the solder on the relay connections. Also, conveniently, the Seville uses the exact same unit as the C5.
GM actually gives you an unofficial way to get the thing apart. The unit unbolts from the hydraulic pump easy enough (go in from the wheel well on the Seville). From there, you need to get the cover off to access the PCB, but it is sealed on with some sort of glue. Also, the unit is filled with some sort of gel, presumably for water-proofing. That last bit is the key. There is a hole in the housing they use to fill the EBCM with the gel, that is also sealed with gel. If you drill that hole out slightly, you can thread a bolt in which pushes on the cover from the inside without breaking it (which will happen if you try to pry it apart due to it being made out of cheap cast aluminum.
Once it is apart, you're looking right at the PCB. Here it is. Can you see the failed connection? Hint, it's the one that I drew a red circle around.
I re-flowed the solder on all 5 attachment points of the internal relay. Resealed it with some RTV, then put it back on the car. She's driven it for about a month now with no issues.
03 Seville SLS EBCM Repair
03 Seville SLS EBCM Repair
You do not have the required permissions to view the files attached to this post.
Re: 03 Seville SLS EBCM Repair
That's pretty satisfying. I was also watching C5 videos so I recommended that fix immediately. Cool that it's the same part. Same era and same system capability (Stabilitrack) so that makes sense.