LymanSS

Hi All,

My 2002 Z06 has been off the road for about a year, and during that time it seems to have acquired some serious electrical issues. I've been reading the very helpful posts by Bill Curlee, and am hoping to narrow down the causes before I commence with tearing everything apart. Any help in pinning down the diagnosis, would be greatly greatly appreciated!

So... here's the story:

Background:
The car was last in use in the summer and fall of 2014. It was then stored outdoors, under a cover. When I went to drive it again in the summer of 2015 I topped up the battery, but it wouldn't start and the DIC listed too many failures to even record. I kept it off the road for the summer, under a cover most of the time.

Today I pulled apart the ground connectors just aft of the headlights and sanded down the male side of the connectors to clear off the corrosion. This has reduced the number of failures, but the car still doesn't run.

Here's where it stands now:

• Turning the key to the "run" position initiates the usual pre-start sequence, but the DIC soon starts throwing codes
• Turning the key to "start" does not appear to do anything
• The DIC says "Reduced Engine Power" and "Service Stability Control"
• The radio buttons light up but the radio won't turn on
• The HVAC turns on and the fans run
• The doors will lock and unlock in response to the interior lock buttons and the remote. But the horn doesn't sound to indicate that the alarm is armed. However the horn will sound if I press horn button on the steering wheel
• The brake lights, blinkers, and hazard lights work
• The small amber light on the rear view mirror turns on, but the map lights will not turn on
• The airbag disabled light (on the center console) lights up, as I have the airbag turned off
• Neither window responds (the right side was already acting up last summer)
• The trunk release does not work

The carpet feels damp, but the BCM and the rest of the stuff beneath the passenger side toe-board appear and feel dry. I haven't removed them yet.

Right now I think my next steps are:

1. Track down the source of moisture.
2. Inspect the BCM for signs of buildup or corrosion as illustrated in post 13 of this thread and if necessary clean the board and connectors.
3. Go through the diagnostic process suggested in post one of this thread

Any advice or suggestions that anyone could offer would be tremendously helpful.

Thanks!

Scott

dadaroo

First thing you need to do is have the battery load tested to make sure it is good.

Leaving a car outside long term with a cover on it will create a terrarium inside the car. You may have condensation inside many things. In particular the BCM.

Make sure the battery is good and we can go from there.


Mr. Sam

Bill Curlee

WHEN,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,, you have a OVERWHELMING list of DTCs and every damn light on the IPC on,, It "USUALLY" tells me that you have a SERIAL DATA BUSS issue.


N O R M A L Y,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, Its caused by a **** POOR connection in the power plug for the SCM, LDCM or RDCM connector. And the SPECIFIC reason is a SPREAD APART FEMALE PIN.

The Male pin rattles around inside the female pin like a 30 year career *****. Thus,, the module turns ON & OFF rapidly due to vibration and that poor connection corrupts the serial data buss with output signal noise on the serial data buss.

Se if you have a bunch of NO COMMS messages!


POOR LDCM POWER CONNECTOR FEMAL PINS:



GUESS, which specific pin is SPREAD APART????????

Bill

jdvann

When disconnecting these modules the SCM, LDCM or RDCM, or any module for that matter for inspection, does the battery need disconnect first? I ask only because I hate all the clicking of relays and such that occurs on reconnect.

thanks in advance....I am tracking similar issues as listed above is why I asked on this thread.

Jim

Bill Curlee

Its always a good idea to disconnect the negative cable when working on any , module especially the BCM.

The Door modules have an ALWAYS HOT wire in that connector so be careful and dont short it to any other pin or ground.

I work on most connectors HOT but, Im careful..

BC

jdvann

Thanks BC...will do. But no problem if just a visual inspection?
Jim

LymanSS

Hi All,

First off, thanks for the helpful and informative responses, and sorry for my own slow reply. I've had to neglect the car for the past few months due to other priorities, but I'm hoping to get it straightened out in time to enjoy some good driving this summer and fall.

Here's the update since I last posted:

1. Following Mr. Sam's advice, I started with a fresh battery (which I just installed today)

2. Since my initial post, I took measures to ensure that the car was clean and dry inside. I cleared all of the drains (including the udders near the driver's side cowl, and the drain near the battery). I also bought ten pounds of silica gel and left it in the car for the past few months. It's dry as a bone in there now. (Before I could often see fog on the inside windows as the temperatures dropped.

3. I re-pulled the codes after reinstalling the battery. The full set of codes is in the attached image.

Basically I think Bill Curlee's suggestion of poor connections to the BCM, LDCM and RDCM makes sense, as I'm seeing a current code for NO COMM on the BCM, and I see historical codes for lost communication on the door modules. I also see a NO COMM error on the HVAC, and I'm getting no power-up on the radio.

The observed symptoms are identical to what I described in my first post. I'm thinking that tomorrow I should try looking for the loose connectors Bill Curlee described. Any other suggestions?

Thanks again!!

Scott


Image of list of codes:

73Corvette

Have you used the DIC to pull codes... most of those appear to be history codes... I would clear them, drive the car and then pull the codes before killing it to see what the current codes are IF any...

Bill Curlee

I agree!! Clear
ALL that old stuff and then see what comes back.

ThumperNC24

I'm having an issue with this connector as well but mine does not look so obviously bad.

Is there an easy way to just replace this connector?

Bill Curlee

Sure, find a replacement OEM pig tail connector and splice it on to the harness..

ThumperNC24

Which wires are for what? I have that black plug unplugged and all the passenger side stuff still works but none of the drivers stuff does.

Pro Street

Having the same problem with the connector on a 03 vert. Anyone have a part # for the female connector?

Greg_E

I think these are Delphi part numbers. They are just the plastic shells. You would need to order the pins or sockets and crimp them on the existing wires.
I don't know where to buy the repair pigtails, if anyone even makes them. You wouldn't need these if you just replace the contacts but the part numbers may help you find a pigtail assembly.

LymanSS and Thumper:
Wire colors shown are for a 2002 or 2003. Same for both years.

LymanSS

Hi All,

Thanks again for all the great advice. It's been a little while since I got to touch the car because I've been traveling for work. Now I'm moving so I need to get it working or have it towed to my new home. It'd be nice to drive it home, so I'm doing my best to solve it in the next 48 hours.

So, following the advice above, I've made sure the interior is dry, installed a fresh battery, and cleared the codes. What come back immediately is a NO COMMS message for the bcm, IPC and hvac. I also get intermittent codes for other stuff like door modules, traction control, etc.

I've pulled the door accordions and inspected the connectors there. They look like new. I've also pulled the bcm and it appears totally dry and the connectors look fine. I checked bcm fuses too and they appear fine. I've checked the grounds near the front wheels and cleaned what little corrosion I could find.

I should note that there was clogging in the udders at some point and the cabin used to get pretty fogged up. The carpets felt wet too. This hasn't been the case for at least six months.

Any ideas would much appreciated. And thanks again for all the good guidance so far.

Scott

LymanSS

Hi All,

I've been thinking about this all day, and re-reading Bill Curlee's famous posts. Now that I've dug into the wiring a little more it makes more sense to me. I've got tonight to try to get the car going, and if that fails I'm having it towed. So here are my plans:

1. Disconnect the top of the Star 2 connector and see if this improves anything. Also check the quality of those pins. If this solves the problem, great - I know it's a door module or a seat module

2. Disconnect the door connectors (I didn't do that last night due to lack of a flashlight. Check for bad pins as Bill's post points out. Clean any oxidation

3. If I have no success with the door module connectors I'll try the driver's side seat connectors, but I'm not confident I can get those out today

4. If all of that fails I'll try to jump the BCM to the PCM as described in one of Bill's posts.

If jumping the BCM to the PCM is effective, is it safe to drive the car in this state? I need to transport it about 15 miles.

Anyone have any other ideas?

Scott

Bill Curlee

Scott Call me if you need more help PM SENT!

Bill

73Corvette

Hey Bill I had asked Sam to please post the outcome of the PM and Calls... I enjoy following these for education and appreciate seeing what the issue and the fix were...Thanks

LymanSS

Hi All,

Another update in this slow epic. As of my last posts, I was trying to get the car running so I could move it to my new house. Unfortunately, despite some direct assistance from Bill Curlee, I didn't manage to get it running in time and ended up having it flat-bedded to my new place.

My final attempt to get the car started involved directly linking the body control computer to the PCM, bypassing the common trouble makers such as the door control modules and the seat control module. I did my best to follow Bill's instructions (both verbal and from another post) so I *think* I did it right. Since this didn't work, it leads me to suspect the body control module may be malfunctioning.

I have now removed the BCM from the passenger footwell and opened it up for examination. It is bone dry (and was at the time of my last post) but I believe it has been exposed to water before. What I'm not sure of is whether there's residual damage or any sort of build-up that might be causing it to malfunction.

Below is a picture of the most suspicious looking parts of the board. If you look closely you can see white streaking in some areas. One connector seems to have some sort of white-ish build up. Is this the sort of stuff that could cause a malfunction?

My plan at this point is to get some electronics cleaner and a soft brush and attempt to clean this up. Then I'll stick it back in the car, clear the codes and see what happens. Anyone have any other suggestions?

Thanks!!

Scott




BCM from 2002 Z06

cloud 9

I just ran my dtc's the other night. Car is running fine, just looked for the hell of it. I have a couple NO COMM codes. I cleared everything as I thought some were older history ones. I will get it out and drive it around and see how many come back. I'll be watching this thread to see the results and I will post any findings I have.