Mr. Curlee-
I have a 03 Z06 and been having a frustrating electrical problem and if possible, I could use some suggestions. Every time I take my car out of the garage for a ride it will start drive fine. Every now and then the security light will come on solid while driving. If I turn off the vehicle while the light is on (solid not flashing) and try to start the vehicle back up it up, it will not even crank the starter. When this happens, I run the codes it has No Communication with BCM and a hand full of other IPC, SDM Codes. If I disconnect the battery and reconnect it, normally it will reset will start up and drive fine until lately.
Recently the vehicle has been driving well with no security light coming on, but when I started it up after making a stop it would not start like before with the same symptoms. Some of the symptoms are the windows will not work, Service Engine, Reduced Engine ect. will occur. When I run the codes the No Communication with the BCM comes up, IPC codes, SDM codes ect. Yesterday it happened again and I disconnected the battery and it would not reset itself, even after multiple attempts. I waited a few hours and it must of reset on its own. I noticed it seems to do it more when it is really hot out. In addition, I like to add my BCM may have got wet before I owned it. Any ideas will be huge help!

 

A very good article I'm impressed!!!

By the way according to your detailed fingerprint you are wanted in Kansas!!! LOL

 

Mr Bill,

I hope you can help me, or at least point me in the right direction. I have read every post in this thread and I have not seen this problem I am having.

About two weeks ago I start my 2000 A4, I look down at the DIC and it says "pull key, wait 10 seconds". The engine is already running so not knowing what will happen, I shut off the engine, pull the key, start it and now it says "service column lock".

It does this almost everytime I start it. The pcm fuel shut off evidently was already reprogramed by the previous owner (I am the 2nd owner), since I can drive it, and have been since with no problem other than the message.

What would happen one day if I drive off with the pull key message?

I have been shutting it off, pulling the key, not waiting more than a few seconds, or until the DIC goes blank, and then starting it and the pull key message is gone, but the column lock message is there.

I am in the process of reading thru the column lock faq, but I have yet to see my exact problem. From what I have read, when the pull key message appears, the engine will not even start.

Any thoughts, recomendations, advice?

Thank you

 

I'd buy a CLB and install it ASAP before your column decides not to unlock.

 

Thank you for the link, but my steering wheel does not lock as it is now. Something has already been done to it since I can drive over 2 mph (no fuel cut off), and the wheel does not lock. It makes a buzzing sound like it is locking/unlocking but doesn't actually do it.

I just need to figure out why it started giving that message, and I think my next step is to remove the knee bolster/bcm cover area, and check and see what has been done to it by the previous owner.

Thanks

 

Thank you Sir, I have had my first vette less than a week, 2000. Day after i got it home the blinkers and flashers failed, replaced the flasher with the gm part and all was well for a couple hours and now nothing! Before i send off for the by pass i would like to know where the flasher rellay is grounded on the car so i can clean it if need be???? Nervous about working on this car cause it is so new to me. This is a great forum and Thank You

 

Read and POST the DTCs using the internal DTC routene and post thhe DTCs that come up. Thats the only way to get to the root of the issue.

BC

 

For the last month or so my HUD has intermittently been acting up. The display always displays something, so I don't believe it is anything with the HUD unit, but half the time all I get is " -- -- " (or the middle lines of where the two digits would be). I monitored the battery for the last week or so and noticed it fluctuating during driving. I was also getting random ABS/Active Handling and Engine codes.

I stopped by Autozone tonight and sure enough there was only about 65% charge, so I picked up a new battery. To my suprise, the voltage while I was driving was lower (13.8 V) that it was with the bad battery (14.1 V) and the HUD was not functioning. I've gone through my service manual, and didn't find a lot of help.

I have left it unplugged overnight to try to reset everything, that did nothing.

Any help would be much appreciated!

 

WOW!!! I can't believe this thread has been going on this long! It's amazing to see everyone helping each other out, hopefully I'll be so lucky.

Here's my problem.....I just did some fairly involved work on my car (removed headers and had them coated, and also installed the DRM brake ducts) nothing crazy but still stuff that had me working around alot of the wiring that I suspect would be related to my problem.

So, here's my problem....when I first took the car out for a test drive everything was working as normal, except the right signal was flashing quickly.

Thinking that I was simply looking at another simple ground problem, I cleaned the ground contacts behind the headlights and then looked things over again.......well I then noticed that my right rear brake lights weren't working (now they're back to working) but the signal lights were and at the same time my driver's lights were now flashing quickly, and my left side reverse light wasn't working.

Can anyone point me in the direction of which ground would be related to all of these things? I'm hoping I can get this taken care of quickly, I'm heading in for surgery tomorrow and need the car to be ready for a drive down to Dover on Friday.

Thanks.

Matt

 

Matt

Try this:

Cycle the emergency flasher button ON and OFF 10-15 times and make sure it OFF. Then check the blinkers.

Let me know if it hanges the symptoms.

BC

 

Hi Bill, thanks for getting back to me so quickly.

I've cycled the hazards 15 times with no change what so ever to the symptoms. However, I have checked and verified that the interior lights aren't flasing as is common when you have a ground problem, and my reverse lights aren't functioning at all when the car is in reverse, but as I mentioned the right light flashes when using the fob to lock the car.

Thanks again for your help.
Matt

 

Update:

Alright, something is really messed up here.

I've messed around with the grounds behind the headlights again trying to get everything cleaned up, and now.....
-my front signals are still flashing quickly and I now have no rear signals.
-my interior lights are flashing in time with the signals
- I have no reverse lights
- when my headlights are on, my signals flash once and then stay on
- my alarm goes off when I use the fob
- when I press the brake pedal, the interior lights turn on, but the break lights don't...

 

Found the freakin thing!!

Was the ground by the rear lights.

 

No one has ever seen the "-- --" on the HUD before? I've started going through grounds too but nothing yet. I have noticed that when I use the turn signals the voltage drops 0.4 to 0.7 volts, which seems like a lot to me.

 

Well scratch this.....about 20 minutes into my 3 hour drive everything went crazy again!!! I'll be looking into this further over the weekend.

Here's where I stand.

- No signals (interior lights flash in time with the signal switch at a rapid pace) except when I'm driving with the headlights on, in which case the signal indicator clicks once, and then stays on.
- No brake lights
- Interior lights light up when applying the brake pedal
- No reverse lights
- No running lights
- Can't lock the car using the Fob without the alarm going off.

I've already cleaned the grounds at the tail lights, and by the running lights, and I got fed up and cut out the grounds behind the headlights and put them onto one ground lug.

 

hey, I got all these readings today but the only thing different than what you covered in the initial post is nothing on my passenger side door is working. My window won't roll down and the door wont unlock unless i unlock it manually. I checked the fuse and it's fine, its not blown. Anyones help would be muc appreciated.
Thanks in advance,
Mike

 

90% of all my electrical problems, including pass. window was a 'pinched' ground wire going to pass. door. dealer even replaced my main computer...which fixed nothing...when he found the bad ground wire, he put my old computer back in. and only charged 300 for the 'search'..Still have ABS/ traction control not working....'nother subject..tle

 

Thanks man, I went out to start cleaning my ground connections today, and tried to crank my car up to back it up on blocks, and my battery was dead. i hooked up a battery charger to it, and it said the battery had 12 volts. then i cranked let it run, turned it off cranked it back up and it was fine as far as the battery goes. So what im asking is does the battery dying have anything to do with my initial problem?
im thinking it does i just dont know why it does.

 

Not every circuit uses a CHASSIS GROUND. Some circuits are DISCRETE and use a SIGNAL wire and a LOW REF wire for signal return. Those Circuits are typically sensor circuits. Heres a prime example a a circuit that DOES NOT use a chassis ground:





If you look in the Power and Ground schematics, you will see that the MODULES involved in the circuit connect to 12 VDC & Chassis ground. IF, the chassis ground for that module was bad, the entire module would not work.

 

Alright, I have another question for you experts out there. This may be a dumb question, but when taking the ground connector apart does it matter which holes the wires go back into when you put it back together, and how to get the thing apart??
Thanks,
Mike