Leaving to go to work this morning, I went to turn off TCS and the car stalled and low engine power came on, I tried again it stalled again. I checked the codes and this is what I came up with...

P1518 PCM to TAC Module Serial Data Circuit -

C1255 EBTCM Internal malfunction

C1278 TCS Temporarily Inhibited by PCM

B2721 PASS-Key Detection Circuit

C2115 Left Rear TPM Sensor Malfunction(I know what this one is)

Any help would be greatly appricated...

Thanks,
Jason

 

Usually when the car starts throwing out several codes it's usually electrical. The electrical guru on the forum is Bill Curlee.
I'll start with the battery. How old is it? Check to see if it's leaking.
A leaking battery with the PCM located directly below can cause problems. You should check the grounds which Mr. Curlee can describe in detail.
I'm sure others will jump in but in the meantime you can check that battery.

 

Here's the codes:
http://forums.corvetteforum.com/showthread.php?t=991533

I recommend at least tightening the battery and cleaning the grounds before contacting Bill. He already gets asked for help a lot, and the least any of us can do is try to do a little on our own before asking for help.

The link to his electrical thread is in the C5 General Sticky.

 

Thanks for the list, I know the codes, but what I don't know is what they mean and how to fix them, and how important each one of them are? Also, if I need to fix any of them asap.

Now that I think about it...this all happened when I turned of traction control. Then it started to go weird.

Thanks,
Jason

 

[QUOTE=leaftye]Here's the codes:
http://forums.corvetteforum.com/showthread.php?t=991533

I recommend at least tightening the battery and cleaning the grounds before contacting Bill. He already gets asked for help a lot, and the least any of us can do is try to do a little on our own before asking for help.

I don't think we should tell people when they can ask for help.
I believe the purpose of this forum is to help members who have questions.
I also believe Bill can speak for himself.

 

Rocknroll, think what you want. Bill's already posted saying how easy it is for people to learn what he's learned, and how much they'd be able to do with a limited amount of knowledge in basic electronics. He's already created two threads here for us, one on grounds and the other on leaks. Those threads, the sticky's and tech tips are for us to try before we ask questions that have been answered before. As I'm sure you well know, electrical gremlins are often caused by loose batteries and bad grounds, and that's why I recommended he give that a shot...better to eliminate those possibilities before going elsewhere. I don't know why you take offense to what I think is sound & practical advice.

Eugene

 

The core code here that is likely your issue is the 1255 EBTCM code. The 1278 and 1518 are a result of going to Reduced Power Mode, pressing the throttle to a lot of TPS % but not getting the corresponding feedback loop due to low RPM inhibited by reduced power.
Definitely try clearing all codes at the DIC touchpad then start and run the car again. If car runs, try to introduce the symptom again by turning the TC off. Check codes again to see what is Current and Historic. If no change at all, check related fuses in both locations. If no blown fuses (or even if you do find a blown fuse) I would pop off the big connector on the EBTCM module that sits between the radiator and power steer pump. spray some water-dissapating isopropyl into the connector and the plug jack on the module then blow out with compressed air. Plug in, reset the battery, try again. It is possible that the EBTCM electricals internally are shorted and need replaced.

Now, it is also possible that the 1518 is your core problem and that the 1255 is an old historic and unrelated and your problem happening when you turned off the TC was purely coincidental. In that case you might have a bad TAC module, which is located on the side of the PCMs bracket behind the front pass wheel well cover. Or one of the TPS redundant feedbacks (TB). Problem is that you cant buy a TAC moduel or TPS sensor from the dealer to patch it in to see if it is the problem or not then return it if it is not the fix; you'd be stuck with the parts. So maybe you have a C5 friend that you can swap the module and TB out with. I have found a bad TAC modules and TPSs before.

The key will be when you clear your codes, which ones come back. EBTCM? TAC/TPS? PASS-key code handshake between BCM and PCM? Sort out which is the root problem, then come back here and post. I can certainly help out here as I have done a lot of troubleshooting on the electrical systems of my customers cars.


Robert / Gen 3 MS

 

Eugene,
I agree with your "sound & practical advice". That's the way I am. But not everybody is like that. I just try to give people the benefit of the doubt and try to help without being critical of their approach.
Rock

 

Nice write-up Robert!
I'm anxious to see what Jason comes back with.

 

Thanks alot for the help!

I will give a look today after work and post what I find.

Thanks for all the help...

Jason

 

Well, after a day or so since the the car not starting. I just checked the codes...the only code I am showing is C2115 H C ...which I expect, I really need to change the Left rear tire sensor.

so, I think all is ok...for now.


Thanks to everyone who replied for all your help!!!!!!!

Jason

 

Jason,
Have you tried reprogramming the tire sensor?
Sometimes that's all it takes and may save you from buying one.
Here's the link that takes you through the steps:
https://www.corvetteforum.com/techti...D=77&TopicID=1