SunnyRainbowHeart

Most recent episode: After driving my year 2000 C5 for 2 hours on a freeway at 70 mph I stopped somewhere and turned off the engine then 10 minutes later tried to restart and ZERO SOUND. Someone tried to jump start me several times and same thing: engine wouldn't even turn over however, windows, horn and lights worked. It was suggested by jumpstarter and by AAA tower that diagnosis could be: (1) BATTERY (No; have new battery); (2) ALTERNATOR (No; have new alternator); (3) STARTER (my mechanic says no); (4) VOLTAGE REGULATOR (as I recall mechanic checked that). My mechanic says for the last two weeks he's had it, it starts up perfectly every time. In addition to the dead engine problem I have others which I wonder are related or not. Before the aforementioned stallout I had taken my car for other problems to another mechanic FOUR TIMES and he can't fix the following. MOST OF THE TIME: (1) my horn doesn't work, (2) the emergency flashers don't work, (3) the turn signal doesn't work. This is not merely inconvenientbut very dangerous. Can someone please help me? Neither of the two mechanics are Corvette specialists but right now I cannot afford the Corvette mechanic. I have to go on an out-of-town job interview this week and I can't trust my 'Vette. Thank you very much!

001pewter

Not sure about the horn, hardly use mine anyway. The flashers are probably from hazard switch. http://www.kd5fx.com/HSwitch/HSwitch.htm that link could help. Not real sure about the not starting, have you checked the codes also they could give some info.

SunnyRainbowHeart

My mechanic iss stumped and said he checked the codes but found nothing.

Venomous_Vette

Sounds like your starter solenoid may be getting too hot and not engaging. Do you have headers?

SunnyRainbowHeart

Hi, 8VETTE7. Thank you. I checked the replies in the other category. I wanted you to know that I also posted there because I was so worried and anxious. BTW, I am overawed by the knowledge, really brilliance, of so many of the posters on this website.

SunnyRainbowHeart

No, VENOMOUS VETTE. No headers. Thank you for your reply.
( I can't find the THANK YOU button. I'm new on this site, have seldom posted but am nonetheless embarrassed. Sometimes I can find the THANK YOU button but other times all the responses are just lumped together one after the other and no THANK YOU button is visible.)

bigvic

I had this same issue happen with one of my old trucks which was a 2007 GMC Sierra. That issue happened a few times on me, the truck would work normal again for a few weeks then finally it happened one last time and wouldn't come back at all.

Turns out my body control module (BCM) was fried. Diagnosed it by putting a known working BCM from a similar truck in there and my truck fired right up.

I put in a new BCM, had the dealer reflash the BCM, and no more problems after that.

bigvic

OP, this is good information. Don't just start blindly throwing parts at your problem trying to fix it. For example in your cross thread in the tech section someone is saying since your hazards aren't working, it has to be the switch that is bad and it's only a $50 part.

Since the no start issue is an intermittent problem, you will have a tough time diagnosing the issue unless you have someone to diagnose it when it actually happens.

The good news is that with my theory (it's just a theory, so don't go buy any parts yet) is that the BCM controls all of the functions of your car that you are having issues with. Your horn, flashers, turn signals, starter and all other electronic functions go through the BCM. I would be willing to bet if you trace the horn, flasher, etc. problem to the BCM and have it replaced, it will also solve the intermittent no start issue.

For me, I did a ton of research and just happened to have another functional BCM available to swap out to test when my BCM finally crapped the bed. What was most frustrating is that it would always happen at the worst time. We had the camper hooked up and the family was about to head out on a long trip when it stopped.

Good luck and I hope you figure out what is wrong. Please keep us posted.

KnightDriveTV

Pretty easy diagnostic flow to figure out. A pure dead/no start condition is early in the electrical system and pretty stupid simple to test for. My advice..find new "mechanics"...because you're guys are parts changers, not troubleshooters.

bigvic

Technically, I am not incorrect in saying the BCM controls the horn in response to the OP’s described condition. Yes, I can read a wiring schematic and don’t disagree that the horn is controlled by the steering wheel, but can also be controlled by the BCM by way of the fob in which you prove my point.

In the OP’s original post, he states most of the time, the horn, flashers, etc. don’t work. Let me ask you, how often do you, or should I say most of the population witness the function of your horn and flashers by actually pressing the steering wheel button and hazard switch vs. using your key fob to lock your doors. For me, I double press the fob 4-5 times a day hearing my horn and seeing the flashers everytime I exit my vehicle vs. maybe once a month on the horn button and usually never on the hazard switch. Therefore, most of the time in my experience the BCM is in control.

This is in no way a knock on the OP, but most everyone I know that doesn’t work on their own vehicles or understand schematics would tell me their horn was broken if it didn’t honk from the key fob without verifying by pressing their steering wheel button.

It could be a huge coincidence that all these issues started happening together at the same time, but let me ask you this…What is the common denominator that could be affecting all these issues intermittently around the same period of time? Again, I’m not saying blindy buy a new BCM, but if it can get tested while experiencing any of these symptoms, it should become obvious whether that is the issue or not.

I’m certainly not trying to get in an internet pissing match with you, but I offered up my experiences with the same symptoms and what my cure was. I’ve been lurking on this forum since 2005 and just now posted my first post because this road the OP is going down if very familiar and very frustrating. I’m just trying to help, so that in itself should say a lot.

I’ve given my advice and take it for what you paid for it, but I’m not going to keep defending it since I don’t want to derail the thread. You seem very smart and able to troubleshoot as well, but from your posts you are thinking in binary…”if it’s not off it must be on”. You need to account for the human factor as well like I explained above. From the OP’s original post there isn’t enough information to hear his/her symptom, look up a schematic, and say “it must be this switch, replace it for $50”.

Also, don’t discount and run off low post count posters. In my experience you can learn a lot more by listening more and posting less.

Cheers

bikeriderga

Sounds like part of the anti theft system from what you are describing, There are two parts to this, one comes from the PCM and one is caused by the BCM and TDM either producing errors codes and/or missing codes that the PCM is expecting. Could also be ignition switch or even key related.


You might also try what is listed in this article
http://my.cardone.com/techdocs/pt%2077-0011.pdf

If all else fails, find someone who can read RAW CAN codes, not just OBD 2 codes. ODB 2 does not report all signals coming on the CAN bus.

Best of luck and let us all know when it is resolved.

SunnyRainbowHeart

Hi, K.I.T.T.
Same thing with my 'Vette: its happening several times. Once I got a new battery. Happened again. Then I got a new alternator. Happened yet again. Then the 3rd time after doing 70 m.p.h. on the freeway for 2 hours, turning the engine off for ten minutes then not being able to restart. Of course, when I took it to the mechanic where it's been for two weeks until late last night, he said it started up perfectly for him every time. Sunny

ZigZag

I'm no expert for sure but this to me sounds just like what my car did. After trying a few ideas from others I gave the starter solenoid a few healthy hits with a long enough broom handle and bingo ! it started right up. Changed starter and solenoid and not a single problem since. Your symptoms seem to be very similar.