2008 Z06. I just had my motor pulled and rebuilt this spring. I've been fighting electrical gremlins ever since. I've searched a ton to try to find what my problem could be. I pretty much have traction control light on at all times. C0561 code along with that. Only occasionally I'll have ABS pop up and the code with that is C0281/C0550. I'm at my wits end and I'm not sure what else to do for troubleshooting. I really don't want to take it to a dealership but I don't know what to do. They want $125 to even look at the car. And I don't want to replace an expensive part (EBCM) if it's not actually necessary.

Also something that's interesting, while on the track the problem got worse, and even if I turned off AH and TC it would basically reset itself and turn AH back on when the error came up. I also started seeing some weird displays including service shocks and multiple service nanny X. I know the systems are tied together but I saw some stuff that wasn't typical. Just putting around town I only ever have C0561 and the occasional C0550/C0281 that go with the ABS light. It typically doesn't stick around long though.

 

The C0550 is for internal ebtcm fault pretty much if sets replace module. The dealer would have to set it up and program it. C0561 is more serial data concern with ecm and bcm. C0281 rear proportioning valve The EBTCM connector is not fluid friendly (particularly with coolant) and the ground for EBTCM is attaches to block near generator(C105). I would suggest to check connector is clean and dry inside with no corrosion and insulation on wires hasn't blistered. Of course check ground is good and harness isn't chaffing. If that all looks okay you will probably end up at dealer.

 

When you say check the connector, are you referring to the connectors going to the actual module? The EBCM?

 

I can do the labor myself. I'm just trying to avoid ending up at the dealer simply for diagnostics. And I know if I do it myself I'll still have to go to dealership to program it. Still cheaper than having them do the labor.

 

Also, if it wasn't stated earlier, the C0561 is on pretty much all the time. The C0550 and C0281 only pop up on rare occasion and the codes don't go to histories.

 

Yes, the connector itself. The 561 is a serial data code. If during the course of engine R&R something happened to connector or ground isn't quite right you may have these codes. The module has to be programmed to car, the dealer is pretty much it for that. There's no diagnostic charts for the 550 & 561. Going with no trouble until engine repair that's where I would look.

 

Thanks. I'll start there.

 

Anyone else has any experience with this? EBCMs aren't cheap.

 

Do you recall, when the engine was pulled, and lots of things removed and disconnected, if the EBCM CAN cable was disconnected with the battery still connected? Actually, any CAN cable connector should only be R/Red with the battery disconnected and capacitors drained. If so, the EBCM might have simply lost it's place on the CAN and, same as replacement, might need to be resynced on the CAN bus.

 

See if there are any codes in PCM and BCM . If present they may lead to cause of the C0561 SES light does not come on for all DTCs.

 

My bet is a loose ground at the left side of the engine, forward of the engine mount. That is the ground for the ABS module. Make sure the ground is tight to the block.

 

I just hooked up an ABS scanner to it. I'm not sure how to check the PCM/BCM specifically.

 

I checked the ones I could find in the bay. Where is this one exactly?

 

It was pulled by a shop. So I hope the battery was disconnected.

 

GM's description of where G105 is supposed to be: Engine harness, in the engine compartment, lower left front of the engine block above the generator.

Most part stores read the generic OBD2 or PCM codes. BCM probably going to require tech 2. If you had custom tune installed it could be related. Hopefully obd2/PCM code will point to cause.

 

If a shop did the engine deal then work it out with them to correct it. Some kind of arrangement with diagnosis and depending on outcome; the repair. Whether they pay or you split it fairly meaning you pay half or less. Diagnosis should come with a written statement of what caused condition, maybe an opinion of why it failed( disconnecting or connecting stuff with battery connected.). what needs done to correct it and cost. Some shops won't put anything in writing if they don't fix it. Tech will only write declined repair. It's BS but there are some who try to get away with it. IF your paying you should get what you are paying for meaning a diagnosis not a SWAG. and a written "report" for lack of better word related to concern. Then talk to shop manager about how to resolve situation.

 

If you get under the car its just aft of the front timing cover engine left side, about 3 inches up from the oil pan mating surface. It may be easier to see if beyou pull the left front wheel and view it from the wheel well.

 

Thank you very much. That helps. I'll take a look this weekend and see.

 

It's a small business and the guy specializes in head work. I had him pull my heads to replace the head gasket and it ended up being a cracked block and not a head gasket. My point of that story is he was trying to help me out by pulling the motor and reinstalling, but he's not a general mechanic to where I could take it and have him troubleshoot or pay to have it fixed. At least for right now, unless I can directly contribute to it being from his work I don't want to get him involved.

Of course, if it does end up being directly related to his labor, then I'd tell him and try to come to some solution.

 

Decided to jack it up after work and take a look. Only place it was visible from was the left front wheel well. So that's where this video was taken (to give context). As you can see, the ground is completely unhooked from where it's supposed to be (awesome!). There's a small bolt underneath it, I assume that's where it goes? The size of the ground makes me think it should be connected to a bigger bolt, though.

https://youtu.be/pgeTqixe4aI