I have a 2003 vert with 12,000 miles on her. The car sits in the garage all winter with a battery tender on the battery. Every 2 or 3 weeks, I take the car our for a 20 miles ride to move all the fluids around and get everything hot. The following has happened the last two times I took the car out for a spin.

During my 20 mile ride, I notice the check engine light comes on. After I'm done with my ride, I pull all the codes and here is what I get

10 PCNI code P0174H
40 BCM code U1096H
58 SDM code U1096H
80 Radio code U1096H
99 FIVAC code U1096H
A0 LDCM code U1096H
Al RDCM code U1096H
B0 RFA code U1096H

The first time I cleared out all the codes and now they are all back again with an "H" which I believe means it is no longer a current problem. Anybody have any idea what is triggering these codes? Seems there is an intermitant problem that needs to be addressed, but I don't know where to start.

Thanks

 

P0174 is bank 2 too lean. If you clear that one and it returns, then you need to get that checked out.

 

Thanks for the tips.

Where is the "serial data buss connection at the IP" located? Could the installation of the column lock blocker last summer have disturbed some electrical connection somewhere? Please point me in the location where this connection might be loose. I'll look for air leaks around the MAF as well

Thanks for your help.

 

Where do we check the star connector, as I have not been able to find it in the footwell? It is intermittent and kills the IPC when it happens. I am thinking I have a ground issue. Which ground plug would affect this?

 

I cleaned the grounds, near the doors , but did not look at grey wire nor clean the star connectors. Will do this tonight and see what gives.
Awesome pics. Makes sense.
Dave

 

in your data base. When I look at star#2, it addresses most of the codes I am getting ; BCM, AC, IPC, radio, etc. Got pulled of the job by the "little woman," but will go through it tomorrow. Car only has 17 K on it, so there was very little corrosion on the grounds, but it doesn't take much at 12V to impede current flow.
It is kind of fun tracking this stuff down. I need to get manuals-next on my list.
Thanks Again,
Dave

 

Where do you think I should start to track it down? Doors, side grounds, Stars?
Thanks much for the input. I PM'd Bill C., but haven't as of yet head back from him.

 

that a dealer actually replaced the IPC just before I bought it at 14K. Probably thought it was the problem, but shortly after I got it, the IPC started going off and coming back on, so the dealer misdiagnosed it. Oh well, got a new IPC anyway. Now to find the real problem.

 

this Am and cleared the codes. Will wait to see if that has a positive effect. They looked good with all females aligned and no real corrosion. That was easy.

 

From my end, I drove the car twice in the last two days and even took the car over a bumpy road to shake things up. No codes.

When I got my codes the last two times, when I started up the car after the car sitting for two weeks, I didn't hold the key all the way to the right long enough so the car turned over and almost started, but didn't start up and stalled so I had to redo the startup sequence. After doing that, the car seemed to run a little rough for say 20 seconds and then smoothed out. Maybe that triggered off something that caused all those codes (although I can't imagine why). I will have some time this weekend and will check the star connectors, etc. I'm inclined to let sleeping dogs lie unless these codes pop up again.

Thanks for all your input. Boy these are tempermental cars!!!

 

OK,,,,,,,,,, heres where you start!! Pop out BOTH of the black rubber accordion tubes between the doors. Once there disconnected from the door and door frame, pull the wires/harness out of the DOOR FRAME A Pillar till you find the connectors.

You will find TWO connectors. Disconnect the connectors. Carefully examine the the FEMALE pins in the connectors. Look for deformed/bent (one of these is not like the other) pins!



When the pins are deformed / cororoded / damaged, they make poor connections. Usually the power supply pins heat up and that causes them to deform.

If you find deformed pins, use a pick and bend the little tung so that it GRIPS THE MALE PIN BETTER and makes better contact.

I have a spare metal pin that I use to test the female pins and when I fins ones with loose connections, I readjust them.

I bet that clears up your issue. When the DOOR MODULE turns on and off rapidly (poor connection) it corrupts the serial data buss and causes all sorts of weird issues.

BC

 

Bill

thanks for the info. Will start where you suggested if I have this problem pop up again. Right now car seems to be running fine, but intermittant problems always make me nervous. I always have my car on a battery tender if it's going to sit idle for more than 2 days and my battery is new so a low/bad battery is not the issue.

Thanks

 

Also I was just getting 0174 code because I had a loose spark plug. associated with a ticking noise...

 

Hmmmmmmmm,,,,, Your battery (if its fully charged and in proper working order), should support the car sitting idle / in storage for well over 30 Days and easily crank the engine with out issue.

There is ZERO reason that you should have to have a charger connected!!!!

What is your BCM Sleep current draw???

Bill

 

OK,,,,,,,,,, heres where you start!! Pop out BOTH of the black rubber accordion tubes between the doors. Once there disconnected from the door and door frame, pull the wires/harness out of the DOOR FRAME A Pillar till you find the connectors.

You will find TWO connectors. Disconnect the connectors. Carefully examine the the FEMALE pins in the connectors. Look for deformed/bent (one of these is not like the other) pins!



When the pins are deformed / cororoded / damaged, they make poor connections. Usually the power supply pins heat up and that causes them to deform.

If you find deformed pins, use a pick and bend the little tung so that it GRIPS THE MALE PIN BETTER and makes better contact.

I have a spare metal pin that I use to test the female pins and when I fins ones with loose connections, I readjust them.

I bet that clears up your issue. When the DOOR MODULE turns on and off rapidly (poor connection) it corrupts the serial data buss and causes all sorts of weird issues.

BC

 

I cleaned the Star connectors and now on to the door plugs. Maybe I will find the cause of the intermittent on /off of my IPC. So far everything I have checked has been clean and aligned . Car has only 17K and has no corrosion anywhere . New battery.

 

That's interesting! Since my car was new, I always got a ticking noise for the first few miniutes until the car warms up. I always assumed it was a lifter and when the oil heated up and thickened the issue went away. Now you have me thinking. I guess the only way to check this out is to replace all spark plugs and wires since from what I have read, getting the spark plugs out destroys the wires, etc.

 

What?

 

plugs after removing the accordions. These plugs were perfect and shiny clean. Cleaned them anyway. Now will wait to see if the IPC acts up again and throws the communication codes. I wonder if I am going to have to pull the IPC and check for connections at it?
How did we ever put a man on the moon--oh that was not GM!

 

I haven't had any electrical issues in several weeks so I have let sleeping dogs lie since my last post. My use of this car is mostly in good weather on the weekend and short trips (20-30 miles). This car has never seen rain, snow, salt, dirty roads, etc. Well this weekend I did a road trip (80 miles one way) and electrical problems surfaced again. This past weekend, everything was fine until the last 5 miles of my trip (at least that’s when I noticed the DIC message) which said “service the traction control system”. I pulled the codes and got

28 TCS C1291 HC
40 BCM U1096 H
58 SDM U1096 H
80 RADIO U1096 H
99 HVAC U1096 H
A0 LDCM U1096 H
A1 RDCM U1096 H
B0 RFA U1000 H

I cleared all the codes before my return 80 mile trip home and all seemed OK until the last few miles when again I noticed on the DIC “service the traction control system”. After I got home and unpacked, I went back into the car to pull the codes and this time only got;

28 TCS C1291 HC

NO u1096 or U1000 codes this time.

I traced the c1291 issue to having no stop lights and I found fuse #8 under the passengers foot well was burnt out and I replaced the fuse --- the tail lights now work so I assume the C1291 problem is history --- although I’m always troubled when a fuse blows as fuses should never blow and when they do there is usually a bigger problem somewhere. Anyway, my big issue right now is getting the U1096 codes everywhere. This smacks as something being loose and on long trips you hit enough bumps and with those hard run flat tires something gets shaken up. ---- When I have time this weekend, I will start where Bill Curlee suggested which is checking the connectors in the accordian rubber boot between the door and the door post. I'll keep everybody informed as to what I find. Hope that's it and nothing more

Thanks to all for their ideas and suggestions.