Need advice PLLLLEEEAAASSEE!

I have a '99 C5 Automatic with 36K miles on it, I'm the 3rd owner, and have had it for about 5 months.

The symptoms of the problem are predictable in the order of which things occur....but I can't seem to have the problem repeat itself on a regular basis.
1st happened about 13 days ago on a 20+ mile drive home - and it occurred 5 times before I finally parked safely in the garage.
I drove it the following 3 days, and nothing happened, the problem never repeated itself.
Then I let the car sit for about a week until this morning, and it happened 2 times on the drive into work.

Here's the sequence of events:
1st I notice that the Left Door Control Module light goes out, and nothing works.
The entire door seems to short out.
The door won't even power lock when pressing the LOCK button from the Right Door Control Module.
After about 3-4 minutes, the Diagnostic Info Center starts scrolling thru almost all the Alerts that exist!
Finally ending with "Reduce Engine Power", to which the car automatically turns off my stereo - which is really spooky!!
Then all the needles on each dashboard gauge will totally red line.
To which my response is to pull the car over, and shut the damn thing off.
While in "shut off" mode, the car seems to "reset" itself.....then I'm able to start it up and go along my merry way.
But as soon as I notice the light go off on the driver's door, 99.9% of the time the sequence of events start all over again.
The only variation in these sequence of events, would be the Alerts on the DIC....sometimes the 1st Alert is the "Reduce Engine Power" and then the stereo dies, and then I find a way to pull to the side of the road quickly.

The first time it happened, I visually inspected under the hood, all battery cables were secure and clean.
All fuses seems ok. All fluid levels were ok. Engine temp. was fine. Nothing visual seems out of order.
My driving behavior is pretty standard, and this problem does NOT appear to be triggered by any "user" pattern.
It does not appear to be triggered by outside factors either, it has occurred in warm & cold & dry & rainy, day or night conditions.

In thinking that there might be a short in the driver door somehow, I have tried to open/close the door while the car is running.... to see if the functionality repairs itself.....to which it does not!!
The only thing that seem to reset the problem, is shutting down the car and restarting.

I went to Auto Zone and had the battery tested, which turns out to be fine, it's not even a year old yet.
I then asked the AZ guy to get that computer gadget and see if there were any codes stored in the computer, to which there wasn't.

ANY IDEA'S on what the problem might be????
I'd like to get some experts advice BEFORE taking the car into the dealer and having them charge me a boatload and take advantage of me.

Thank you kindly,
Kim

 

I dont have the solution to your problem, but had some thing very similar occur.

I pulled my Z06 in my driveway backwards, and washed it, and dried it. took it for a drive an hour later and had reduced power and the gauges went to red line. I drove it hard for about 10 minutes, reduced power was not reduced power at all. suddenly everything cleared and it was fine.

I gather backing it in my driveway caused water to get in the computer somehow. My guess is the computer that is mounted under the passeneger side, front wheel well. I have seen some bits of this mentioned in posts about there being a computer mounted up under the car for stereo installs with nav systems (for tapping into gauges.)

I think when I checked codes I had a bunch, which I cleared after the problem went away. this was the only time it ever did it to me.

I dont back in and wash the car in the driveway anymore.
When I install my nav system I have to go into this computer area. I plan to find out if there was a leak of some sort and plan to seal it up, and fix any connections that may need help.

 

That's very odd - your problem sounds weirder than mine.
Here's an update on my problem.....
I did further searching on the forum - and found someone that had the exact problem as me:
http://forums.corvetteforum.com/show...22&postcount=1
I'm heading out to my to check the "codes", thanks to another Thread I found out how to check the codes.
AND do a little wire "wiggle" and see if that helps......if not...then I'm heading to the dealer with a print out of 2 very very helpful threads from this forum.
THANK HEAVEN for this FORUM!!!!

 

There was a link several months ago concerning this problem and it referred to the chassis grounds needing to be cleaned.
Enjoy the ride!!

 

Sounds like a bad ground with everything going whacky. The reduce power could be because one of the engine sensors lost it's signal, which may throw the PCM into a reduce power mode. Check out your ground connections. I think there is a sticky on here somewhere talking about grounds. There is about a half dozen ground lugs on the frame I believe. Good luck.

 

My last C5 had an almost identical problem (99 w/ 30,000) I took it to the dealer and was told the engine bay had been hosed out and water had been sitting near many electrical connections causing a short. After they dried it out I was told it was ready to go , but on the way there they said the same thing was happening again. After some time and a quality sevice tech he narrowed it down to the controlmodule in the door panel,he tied it off and it was perfect except that you couldn't use that door's power accesories until a replacement module was installed. After install one initial problem that was easily fixed with a little tightening of the unit. Hope that help's.

 

Ok, I had a similar problem with a different car, a 2000 Chevy Malibu.

All of a sudden, in our driveway after returning from someplace, all the gauges go haywire and peg themselves.
Back and forth the needles bounced.
Trunk lid pops open and nothing seems to work, horn very weak, while trying to start it, all we get is that clicking noise.

Battery is a Delco freedom and it is glowing bright Green (good).

We have been having problems with our Ignition switch on that car so I install a new switch .... no improvement. (It needed the new switch anyways)

Then I start to think, all signs tell me low voltage, so I check lots of wires, slowly getting closer and closer to the BATTERY which is still showing bright Green.

I measure the voltage on the battery while it's disconnected and it shows 10 volts.

It was a shorted out battery giving only 10 volts.

Good luck

 

Clean them all. I did mine and all my codes went away

 

The other problem that can cause this anomolie is the serial bus star connector that is under the passenger side floor mat. What happens and it appears that you have this issue is that the PCM, BCM, instrument cluster and a few other "smart devices" all communicates to each other on the cars class 2 serial bus. The problem that you describe sounds just like the devices looses communications with the other devices. For instance your dash receives most of its information from the PCM and the BCM, if it looses communications it will no longer be able to display temperature, speed etc. The reason that the car goes into reduced power is that the PCM looses communications with the TAC module which drives the throttle body motor. It is a safety interlock that takes over when the PCM sees a TAC module fault or looses communication with it.

If you lift the passenger side floor mat, you will see a trap door, open the trap door, the star packs are on the left side of the opening. They have what appears to be a plastic grey color cap on the connector, the connector itself is white. One has 4 or 6 wires connected to it and the other has 10 or 12. Remove the grey colored caps and make sure they are clean. While you are in there take a good look and make sure no water had got into that compartment. Your BCM resides in there as well.

 

BINGO!!!!!!

tjwong hit the nail on the head!! Your loosing serial buss data! The PCM and other modules are not communicating properly and the PCM is going in to the default or reduced power mode. Finding that short can be very frustrating. I have a couple of "COMMON" areas to check before you have to take your car to the dealer.

First and most common!

The electrical connections for the drivers and passengers door run through a black rubber accordion tube near the door hinges. If you pull the tube out of the hole that it fits into on the door header, you will be able to access the two electrical connectors. If you examine the wires on the each connector, you will see a ground wire in a CLEAR sheath. The sheath frequently gets pulled back and exposes the bare wires which cam short out the door and serial buss. I had the exact same problem the last time I was in Portsmouth NH on business. I had numerous codes and LOSS OF COMMUNICATIONS and ("U" series codes) fortunately for me I knew that my drivers door control module was intermittent and frequently lost communications which I could easily fix by wiggling the wires inside that accordion tube.

Next area:

The seat control module plug/s (under the passengers and or drivers seat) can get damaged and short out. Examine the electrical plugs and look for broken, shorted burnt or corroded wires.

Let us know what you find

Bill Curlee

 

This may help.

 

All-
The culprit was a ground wire loose which was shorting out the Driver's side Door Control Module intermittenly.....and in turn causing all the haywire electronic problems

The loose ground wire was located under the drivers side dash, not in the drivers side door, or in the accordian section.....but where the wires come thru the door into the body of the car under the dashboard.

I didn't end up taking the car to a dealer, but to my local auto shop, and he charged me $250 in labor only.....there were no parts purchased.

I've been driving the car for 5 days with no problem.....at least not with the electric issue. Now I have a loud crack noise in the rear end every time I drive over the smallest bump. Guess I need to research this new problem now!

 

I guess I better subscribe to this thread.

 

I think I have seen this EXACT ground wire!!! It is actually on the door connector (which isn't in the door). The connector has a clear insulating sleeve which shields two bare wires and the sleeve can ride up on the wire exposing the bare wires. If the bare wires get bent around and touch one of the other wires in the plug, it causes problems. Mine was shorting out the door control module. If I shook the wires inside the accordion tube (quick fix) I would regain use of the door controls. One day while I was on a business trip 200 miles from home, the door module stopped working. I shook the tube and this time the wires shorted out more than just the door module. I got tons of codes and reduced power. I actually separated the accordion tube, pulled out the connectors and saw what was going on with the connector. As soon as I pulled it out and straightened out the wire/s, I cleared the codes and everything returned back to normal.

The wires in question are on the LARGE connector. There is also a small connector in the tube but I believe that its just for power.

BC

 

Could be a bad shock or possibly loose sway bar. Is it right, left, or center that the sound is coming from? Can you tell?